diff --git a/addons_extensions/module_selector_sidebar/__manifest__.py b/addons_extensions/module_selector_sidebar/__manifest__.py
index 53da8e514..5c49c808a 100644
--- a/addons_extensions/module_selector_sidebar/__manifest__.py
+++ b/addons_extensions/module_selector_sidebar/__manifest__.py
@@ -12,4 +12,4 @@
         ],
     },
     "installable": True,
-}
\ No newline at end of file
+}
diff --git a/addons_extensions/project_task_timesheet_extended/models/project_task.py b/addons_extensions/project_task_timesheet_extended/models/project_task.py
index ae3b79e44..400319a2d 100644
--- a/addons_extensions/project_task_timesheet_extended/models/project_task.py
+++ b/addons_extensions/project_task_timesheet_extended/models/project_task.py
@@ -1025,6 +1025,23 @@ class projectTask(models.Model):
         if stage and stage.mail_template_id:
             stage.mail_template_id.sudo().send_mail(self.id, force_send=True)
 
+    def _notify_reassigned_users(self, users, note):
+        self.ensure_one()
+        partners = users.mapped('partner_id')
+        if not partners:
+            return
+        task_name = self.display_name or self.name
+        body = Markup("<p>%s</p><p>%s</p>") % (
+            _("You have been re-assigned to task %s.") % task_name,
+            note,
+        )
+        self.with_context(mail_notify_force_send=True).message_notify(
+            partner_ids=partners.ids,
+            subject=_("Task Re-assigned: %s") % task_name,
+            body=body,
+            email_layout_xmlid="mail.mail_notification_light",
+        )
+
     def _apply_task_stage_users(self, stage, users, reason=False, reassignment=False):
         self.ensure_one()
         if not stage:
@@ -1051,16 +1068,19 @@ class projectTask(models.Model):
         self._post_to_project_channel(note, users.mapped('partner_id'))
         self._send_stage_mail_template(stage)
         if reassignment:
+            self._notify_reassigned_users(users, note)
             self._append_reassignment_history(stage, users, reason)
 
     def _apply_task_stage_user_lines(self, lines, reason=False, reassignment=False, update_assignees=True):
         self.ensure_one()
         self._ensure_task_timeline_rows()
         selected_users = self.env['res.users']
+        replaced_users = self.env['res.users']
         notes = []
         for wizard_line in lines:
             stage = wizard_line.stage_id
-            users = wizard_line.user_ids
+            user = getattr(wizard_line, 'user_id', False)
+            users = user or getattr(wizard_line, 'user_ids', self.env['res.users'])
             responsible_user = getattr(wizard_line, 'responsible_user_id', False)
             if not stage or not users:
                 continue
@@ -1068,22 +1088,33 @@ class projectTask(models.Model):
             timeline = self.assignees_timelines.filtered(lambda t: t.stage_id == stage)[:1]
             primary_user = users[0]
             if timeline:
+                if reassignment and timeline.assigned_to:
+                    replaced_users |= timeline.assigned_to
                 timeline.sudo().write({
                     'assigned_to': primary_user.id,
                     'responsible_lead': responsible_user.id if responsible_user else timeline.responsible_lead.id or primary_user.id,
                     'team_id': stage.team_id.id if stage.team_id else timeline.team_id.id,
                 })
-            notes.append(_("%s: %s") % (stage.name, ", ".join(users.mapped('name'))))
+            line_reason = getattr(wizard_line, 'reason', False) or reason
+            note = _("%s: %s") % (stage.name, ", ".join(users.mapped('name')))
+            if line_reason:
+                note += _(". Reason: %s") % line_reason
+            notes.append(note)
             self._send_stage_mail_template(stage)
             if reassignment:
-                self._append_reassignment_history(stage, users, reason)
+                self._append_reassignment_history(stage, users, line_reason)
 
         if not selected_users:
             raise UserError(_("Please select at least one user."))
 
-        if update_assignees:
-            self.sudo().write({'user_ids': [(6, 0, selected_users.ids)]})
-        self.sudo().write({'involved_user_ids': [(6, 0, selected_users.ids)]})
+        if reassignment:
+            assignees = (self.user_ids - replaced_users) | selected_users
+            self.sudo().write({'user_ids': [(6, 0, assignees.ids)]})
+            self._sync_involved_assignees_from_timelines()
+        else:
+            if update_assignees:
+                self.sudo().write({'user_ids': [(6, 0, selected_users.ids)]})
+            self.sudo().write({'involved_user_ids': [(6, 0, selected_users.ids)]})
         action = _("Re-assigned") if reassignment else _("Timeline users selected")
         note = _("%s: %s") % (action, "; ".join(notes))
         if reason:
@@ -1096,6 +1127,8 @@ class projectTask(models.Model):
             subtype_xmlid='mail.mt_comment',
         )
         self._post_to_project_channel(note, selected_users.mapped('partner_id'))
+        if reassignment:
+            self._notify_reassigned_users(selected_users, note)
 
     def _move_to_selected_stage(self, stage):
         self.ensure_one()
diff --git a/addons_extensions/project_task_timesheet_extended/security/security.xml b/addons_extensions/project_task_timesheet_extended/security/security.xml
index 86cfd666f..44d8b4fdc 100644
--- a/addons_extensions/project_task_timesheet_extended/security/security.xml
+++ b/addons_extensions/project_task_timesheet_extended/security/security.xml
@@ -38,6 +38,28 @@
             <value eval="{'noupdate': True}"/>
         </function>
 
+
+        <function name="write" model="ir.model.data">
+            <function name="search" model="ir.model.data">
+                <value eval="[('module', '=', 'project'), ('name', '=', 'project_project_manager_rule')]"/>
+            </function>
+            <value eval="{'noupdate': False}"/>
+        </function>
+
+        <record id="project.project_project_manager_rule" model="ir.rule">
+            <field name="domain_force">[(1, '=', 1)]</field>
+            <field name="perm_read" eval="1"/>
+            <field name="perm_write" eval="1"/>
+            <field name="perm_create" eval="1"/>
+            <field name="perm_unlink" eval="1"/>
+        </record>
+
+        <function name="write" model="ir.model.data">
+            <function name="search" model="ir.model.data">
+                <value eval="[('module', '=', 'project'), ('name', '=', 'project_project_manager_rule')]"/>
+            </function>
+            <value eval="{'noupdate': True}"/>
+        </function>
         <record id="portfolio_rule_company_projects" model="ir.rule">
             <field name="name">company: Own Company</field>
             <field name="model_id" ref="model_project_portfolio"/>
@@ -48,10 +70,10 @@
             <field name="name">Manager: Own Projects</field>
             <field name="model_id" ref="project.model_project_project"/>
             <field name="groups" eval="[(4, ref('project_task_timesheet_extended.group_project_supervisor'))]"/>
-            <field name="domain_force">[('user_id', '=', user.id)]</field>
+            <field name="domain_force">['|', ('user_id', '=', user.id), ('user_id', '=', False)]</field>
             <field name="perm_read" eval="1"/>
             <field name="perm_write" eval="1"/>
-            <field name="perm_create" eval="1"/>
+            <field name="perm_create" eval="0"/>
             <field name="perm_unlink" eval="0"/>
         </record>
 
@@ -95,11 +117,33 @@
             <field name="groups" eval="[(4,ref('base.group_user')),(4,ref('project.group_project_user'))]"/>
             <field name="perm_read" eval="1"/>
             <field name="perm_write" eval="1"/>
-            <field name="perm_create" eval="1"/>
+            <field name="perm_create" eval="0"/>
             <field name="perm_unlink" eval="0"/>
         </record>
 
 
+
+        <function name="write" model="ir.model.data">
+            <function name="search" model="ir.model.data">
+                <value eval="[('module', '=', 'project'), ('name', '=', 'project_manager_all_project_tasks_rule')]"/>
+            </function>
+            <value eval="{'noupdate': False}"/>
+        </function>
+
+        <record id="project.project_manager_all_project_tasks_rule" model="ir.rule">
+            <field name="domain_force">[(1, '=', 1)]</field>
+            <field name="perm_read" eval="1"/>
+            <field name="perm_write" eval="1"/>
+            <field name="perm_create" eval="1"/>
+            <field name="perm_unlink" eval="1"/>
+        </record>
+
+        <function name="write" model="ir.model.data">
+            <function name="search" model="ir.model.data">
+                <value eval="[('module', '=', 'project'), ('name', '=', 'project_manager_all_project_tasks_rule')]"/>
+            </function>
+            <value eval="{'noupdate': True}"/>
+        </function>
         <record model="ir.rule" id="project.ir_rule_private_task">
             <field name="domain_force">[
                 '&amp;',
diff --git a/addons_extensions/project_task_timesheet_extended/static/src/css/delopyment.css b/addons_extensions/project_task_timesheet_extended/static/src/css/delopyment.css
index c451556fb..e76981969 100644
--- a/addons_extensions/project_task_timesheet_extended/static/src/css/delopyment.css
+++ b/addons_extensions/project_task_timesheet_extended/static/src/css/delopyment.css
@@ -62,22 +62,9 @@
     max-width: calc(100% - 18px);
 }
 
-.o_task_reassign_arrow {
-    padding: 0;
-    margin-left: 2px;
-    min-width: 12px;
-    width: 12px;
-    height: 12px;
-    line-height: 12px;
-    color: #374151;
-    vertical-align: middle;
-}
-
-.o_task_reassign_arrow .fa {
-    font-size: 10px;
-    line-height: 12px;
-}
-
-.o_task_reassign_arrow:hover {
-    color: #017e84;
-}
+.o_task_reassign_button {
+    margin-left: 8px;
+    padding: 2px 10px;
+    line-height: 20px;
+    white-space: nowrap;
+}
\ No newline at end of file
diff --git a/addons_extensions/project_task_timesheet_extended/view/project_task.xml b/addons_extensions/project_task_timesheet_extended/view/project_task.xml
index 3cb84e356..919ec7660 100644
--- a/addons_extensions/project_task_timesheet_extended/view/project_task.xml
+++ b/addons_extensions/project_task_timesheet_extended/view/project_task.xml
@@ -29,7 +29,7 @@
                     <div class="o_task_assignees_inline">
                         <field name="user_ids" nolabel="1" widget="involved_assignee_avatar_user" domain="[('id', 'in', involved_user_ids)]" options="{'no_create': True, 'no_quick_create': True, 'no_create_edit': True}" invisible="is_generic"/>
                         <field name="user_ids" nolabel="1" class="o_task_user_field" options="{'no_open': True, 'no_quick_create': True}" widget="many2many_avatar_user" domain="[('id', 'in', assignee_domain_ids)]" invisible="not is_generic"/>
-                        <button name="action_open_reassign_wizard" type="object" icon="fa-caret-down" title="Re-Assign Assignees" class="btn-link o_task_reassign_arrow" invisible="record_paused"/>
+                        <button name="action_open_reassign_wizard" type="object" string="Re-Assign" title="Re-Assign Assignees" class="btn btn-secondary btn-sm o_task_reassign_button" invisible="record_paused"/>
                     </div>
                 </xpath>
                 <xpath expr="//field[@name='timesheet_ids']" position="attributes">
@@ -293,7 +293,6 @@
         <record id="project.project_task_kanban_action_view" model="ir.actions.act_window.view">
             <field name="view_id" ref="project_task_timesheet_extended.project_task_kanban_task_id_module_project_tasks"/>
         </record>
-
     </data>
 </odoo>
 
diff --git a/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.py b/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.py
index e770eb2d5..0622c2039 100644
--- a/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.py
+++ b/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.py
@@ -63,7 +63,7 @@ class TaskBackStageWizard(models.TransientModel):
         for wizard in self:
             stages = wizard.task_id.project_id.type_ids
             if wizard.task_id.stage_id:
-                stages = stages.filtered(lambda s: s.id != wizard.task_id.stage_id.id)
+                stages = stages.filtered(lambda s: s.id != wizard.task_id.stage_id.id and s.sequence < wizard.task_id.stage_id.sequence)
             wizard.available_stage_ids = [(6, 0, stages.ids)]
 
     def action_confirm(self):
@@ -89,7 +89,7 @@ class TaskRequestTimelinesWizard(models.TransientModel):
                 (0, 0, {
                     "stage_id": line.stage_id.id,
                     "responsible_user_id": line.responsible_lead.id,
-                    "user_ids": [(6, 0, line.assigned_to.ids)],
+                    "user_id": line.assigned_to.id,
                 })
                 for line in task.assignees_timelines.sorted(lambda l: l.stage_sequence)
                 if line.stage_id
@@ -98,7 +98,7 @@ class TaskRequestTimelinesWizard(models.TransientModel):
 
     def action_apply(self):
         self.ensure_one()
-        selected_lines = self.line_ids.filtered(lambda line: line.stage_id and line.user_ids)
+        selected_lines = self.line_ids.filtered(lambda line: line.stage_id and line.user_id)
         if not selected_lines:
             raise UserError(_("Please select users for at least one stage."))
         self.task_id.sudo().timelines_requested = True
@@ -114,18 +114,41 @@ class TaskRequestTimelinesWizardLine(models.TransientModel):
     task_id = fields.Many2one(related="wizard_id.task_id", store=False)
     stage_id = fields.Many2one("project.task.type", string="Stage")
     responsible_user_id = fields.Many2one("res.users", string="Responsible User")
-    user_ids = fields.Many2many("res.users", string="Assignees")
+    user_id = fields.Many2one("res.users", string="Assignee")
     available_user_ids = fields.Many2many("res.users", compute="_compute_available_user_ids")
 
-    @api.depends("stage_id", "task_id")
+    def _get_project_involved_users(self):
+        self.ensure_one()
+        users = self.env["res.users"]
+        task = self.task_id
+        project = task.project_id
+        if project:
+            users |= project.members_ids | project.user_id | project.project_lead | project.project_sponsor
+        if self.stage_id:
+            users |= self.stage_id.involved_user_ids
+            if self.stage_id.team_id:
+                users |= self.stage_id.team_id.team_lead | self.stage_id.team_id.all_members_ids
+        if task:
+            users |= task.user_ids | task.involved_user_ids
+        return users.filtered(lambda user: user.active and not user.share)
+
+    @api.depends(
+        "stage_id",
+        "stage_id.involved_user_ids",
+        "stage_id.team_id",
+        "stage_id.team_id.team_lead",
+        "stage_id.team_id.all_members_ids",
+        "task_id",
+        "task_id.user_ids",
+        "task_id.involved_user_ids",
+        "task_id.project_id.members_ids",
+        "task_id.project_id.user_id",
+        "task_id.project_id.project_lead",
+        "task_id.project_id.project_sponsor",
+    )
     def _compute_available_user_ids(self):
         for line in self:
-            users = line.stage_id.involved_user_ids
-            if line.stage_id.team_id:
-                users |= line.stage_id.team_id.all_members_ids
-            if line.task_id.project_id:
-                users |= line.task_id.project_id.members_ids | line.task_id.project_id.user_id | line.task_id.project_id.project_lead
-            line.available_user_ids = [(6, 0, users.filtered(lambda u: not u.share).ids)]
+            line.available_user_ids = [(6, 0, line._get_project_involved_users().ids)]
 
 
 class TaskReassignAssigneesWizard(models.TransientModel):
@@ -133,10 +156,8 @@ class TaskReassignAssigneesWizard(models.TransientModel):
     _description = "Task Re-Assign Assignees Wizard"
 
     task_id = fields.Many2one("project.task", string="Task", required=True)
-    reason = fields.Text(string="Re-assignment Reason", required=True)
     stage_ids = fields.Many2many("project.task.type", string="Stages", required=True)
     available_stage_ids = fields.Many2many("project.task.type", compute="_compute_available_stage_ids")
-    user_ids = fields.Many2many("res.users", string="New Assignees", required=True)
     available_user_ids = fields.Many2many("res.users", compute="_compute_available_user_ids")
     line_ids = fields.One2many("task.reassign.assignees.wizard.line", "wizard_id", string="Selected Stage Assignees")
 
@@ -146,14 +167,12 @@ class TaskReassignAssigneesWizard(models.TransientModel):
         task = self.env["project.task"].browse(values.get("task_id") or self.env.context.get("default_task_id"))
         if task:
             default_stage = self.env["project.task.type"].browse(self.env.context.get("default_stage_id")) or task.stage_id
-            default_users = task.user_ids
             values.setdefault("stage_ids", [(6, 0, default_stage.ids)])
-            values.setdefault("user_ids", [(6, 0, default_users.ids)])
             if "line_ids" in fields_list and default_stage:
                 values["line_ids"] = [
                     (0, 0, {
                         "stage_id": stage.id,
-                        "user_ids": [(6, 0, default_users.ids)],
+                        "user_id": task.assignees_timelines.filtered(lambda line: line.stage_id == stage)[:1].assigned_to.id,
                     })
                     for stage in default_stage
                 ]
@@ -173,34 +192,46 @@ class TaskReassignAssigneesWizard(models.TransientModel):
                 if stage.team_id:
                     users |= stage.team_id.all_members_ids
             if wizard.task_id.project_id:
-                users |= wizard.task_id.project_id.members_ids | wizard.task_id.project_id.user_id | wizard.task_id.project_id.project_lead
-            wizard.available_user_ids = [(6, 0, users.filtered(lambda u: not u.share).ids)]
+                users |= wizard.task_id.project_id.members_ids | wizard.task_id.project_id.user_id | wizard.task_id.project_id.project_lead | wizard.task_id.project_id.project_sponsor
+            wizard.available_user_ids = [(6, 0, users.filtered(lambda u: u.active and not u.share).ids)]
 
-    @api.onchange("stage_ids", "user_ids")
-    def _onchange_stage_or_users(self):
+    def _get_default_user_for_stage(self, stage):
+        self.ensure_one()
+        timeline = self.task_id.assignees_timelines.filtered(lambda line: line.stage_id == stage)[:1]
+        return timeline.assigned_to.id if timeline else False
+
+    def _preferred_existing_line(self, stage):
+        self.ensure_one()
+        lines = self.line_ids.filtered(lambda line: line.stage_id == stage)
+        return lines.filtered(lambda line: line.user_id or line.reason)[:1] or lines[:1]
+
+    @api.onchange("stage_ids")
+    def _onchange_stage_ids(self):
+        Line = self.env["task.reassign.assignees.wizard.line"]
         for wizard in self:
-            existing_users_by_stage = {
-                line.stage_id.id: line.user_ids.ids
-                for line in wizard.line_ids
-                if line.stage_id
-            }
-            common_user_ids = wizard.user_ids.ids
-            wizard.line_ids = [(5, 0, 0)] + [
-                (0, 0, {
-                    "stage_id": stage.id,
-                    "user_ids": [(6, 0, common_user_ids or existing_users_by_stage.get(stage.id, []))],
-                })
-                for stage in wizard.stage_ids.sorted(lambda s: s.sequence)
-            ]
+            lines = Line
+            for stage in wizard.stage_ids.sorted(lambda s: s.sequence):
+                existing_line = wizard._preferred_existing_line(stage)
+                if existing_line:
+                    lines |= existing_line
+                else:
+                    lines |= Line.new({
+                        "stage_id": stage.id,
+                        "user_id": wizard._get_default_user_for_stage(stage),
+                    })
+            wizard.line_ids = lines
 
     def action_confirm(self):
         self.ensure_one()
-        selected_lines = self.line_ids.filtered(lambda line: line.stage_id and line.user_ids)
+        selected_lines = self.line_ids.filtered(lambda line: line.stage_id in self.stage_ids and line.user_id)
         if not selected_lines:
             raise UserError(_("Please select stages and new assignees."))
-        self.task_id._apply_task_stage_user_lines(selected_lines, reason=self.reason, reassignment=True)
+        if any(not line.reason for line in selected_lines):
+            raise UserError(_("Please enter a reason for each selected stage."))
+        self.task_id._apply_task_stage_user_lines(selected_lines, reassignment=True)
         return {"type": "ir.actions.act_window_close"}
 
+
 class TaskReassignAssigneesWizardLine(models.TransientModel):
     _name = "task.reassign.assignees.wizard.line"
     _description = "Task Re-Assign Assignees Stage User Line"
@@ -208,15 +239,39 @@ class TaskReassignAssigneesWizardLine(models.TransientModel):
     wizard_id = fields.Many2one("task.reassign.assignees.wizard", required=True, ondelete="cascade")
     task_id = fields.Many2one(related="wizard_id.task_id", store=False)
     stage_id = fields.Many2one("project.task.type", string="Stage")
-    user_ids = fields.Many2many("res.users", string="New Assignees")
+    user_id = fields.Many2one("res.users", string="New Assignee")
+    reason = fields.Text(string="Reason")
     available_user_ids = fields.Many2many("res.users", compute="_compute_available_user_ids")
 
-    @api.depends("stage_id", "task_id")
+    def _get_project_involved_users(self):
+        self.ensure_one()
+        users = self.env["res.users"]
+        task = self.task_id
+        project = task.project_id
+        if project:
+            users |= project.members_ids | project.user_id | project.project_lead | project.project_sponsor
+        if self.stage_id:
+            users |= self.stage_id.involved_user_ids
+            if self.stage_id.team_id:
+                users |= self.stage_id.team_id.team_lead | self.stage_id.team_id.all_members_ids
+        if task:
+            users |= task.user_ids | task.involved_user_ids
+        return users.filtered(lambda user: user.active and not user.share)
+
+    @api.depends(
+        "stage_id",
+        "stage_id.involved_user_ids",
+        "stage_id.team_id",
+        "stage_id.team_id.team_lead",
+        "stage_id.team_id.all_members_ids",
+        "task_id",
+        "task_id.user_ids",
+        "task_id.involved_user_ids",
+        "task_id.project_id.members_ids",
+        "task_id.project_id.user_id",
+        "task_id.project_id.project_lead",
+        "task_id.project_id.project_sponsor",
+    )
     def _compute_available_user_ids(self):
         for line in self:
-            users = line.stage_id.involved_user_ids
-            if line.stage_id.team_id:
-                users |= line.stage_id.team_id.all_members_ids
-            if line.task_id.project_id:
-                users |= line.task_id.project_id.members_ids | line.task_id.project_id.user_id | line.task_id.project_id.project_lead
-            line.available_user_ids = [(6, 0, users.filtered(lambda u: not u.share).ids)]
+            line.available_user_ids = [(6, 0, line._get_project_involved_users().ids)]
diff --git a/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.xml b/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.xml
index 855ce3bd1..172787ec9 100644
--- a/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.xml
+++ b/addons_extensions/project_task_timesheet_extended/wizards/task_reject_reason_wizard.xml
@@ -79,9 +79,9 @@
                 <field name="line_ids" nolabel="1">
                     <list editable="bottom" create="0" delete="0">
                         <field name="stage_id" readonly="1" force_save="1" options="{'no_open': True}"/>
-                        <field name="responsible_user_id" force_save="1" options="{'no_create': True, 'no_open': True}"/>
+                        <field name="responsible_user_id" force_save="1" domain="[('id', 'in', available_user_ids)]" options="{'no_create': True, 'no_open': True}"/>
                         <field name="available_user_ids" column_invisible="1"/>
-                        <field name="user_ids" string="Assignees" widget="many2many_tags" domain="[('id', 'in', available_user_ids)]" options="{'no_create': True, 'no_open': True}"/>
+                        <field name="user_id" string="Assignee" domain="[('id', 'in', available_user_ids)]" options="{'no_create': True, 'no_open': True}"/>
                     </list>
                 </field>
                 <footer>
@@ -100,16 +100,14 @@
                 <group>
                     <field name="task_id" invisible="1"/>
                     <field name="available_stage_ids" invisible="1"/>
-                    <field name="available_user_ids" invisible="1"/>
-                    <field name="reason" placeholder="Enter re-assignment reason..."/>
                     <field name="stage_ids" widget="many2many_tags" domain="[('id', 'in', available_stage_ids)]" options="{'no_create': True, 'no_open': True}"/>
-                    <field name="user_ids" widget="many2many_tags" domain="[('id', 'in', available_user_ids)]" options="{'no_create': True, 'no_open': True}"/>
                 </group>
                 <field name="line_ids" nolabel="1" invisible="not stage_ids">
                     <list editable="bottom" create="0" delete="0">
                         <field name="stage_id" readonly="1" force_save="1" options="{'no_open': True}"/>
                         <field name="available_user_ids" column_invisible="1"/>
-                        <field name="user_ids" widget="many2many_tags" domain="[('id', 'in', available_user_ids)]" options="{'no_create': True, 'no_open': True}"/>
+                        <field name="user_id" string="New Assignee" force_save="1" domain="[('id', 'in', available_user_ids)]" options="{'no_create': True, 'no_open': True}"/>
+                        <field name="reason" required="1" force_save="1"/>
                     </list>
                 </field>
                 <footer>