diff --git a/app/assets/javascripts/discourse/app/components/group-manage-save-button.js b/app/assets/javascripts/discourse/app/components/group-manage-save-button.js
index 3c7e17d634d..3999c2b7563 100644
--- a/app/assets/javascripts/discourse/app/components/group-manage-save-button.js
+++ b/app/assets/javascripts/discourse/app/components/group-manage-save-button.js
@@ -1,5 +1,4 @@
 import Component from "@ember/component";
-import DiscourseURL from "discourse/lib/url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { popupAjaxError } from "discourse/lib/ajax-error";
@@ -37,26 +36,7 @@ export default Component.extend({
 
       return group
         .save(opts)
-        .then((data) => {
-          if (data.user_count) {
-            const controller = showModal("group-default-notifications", {
-              model: {
-                count: data.user_count,
-              },
-            });
-
-            controller.set("onClose", () => {
-              this.updateExistingUsers = controller.updateExistingUsers;
-              this.send("save");
-            });
-
-            return;
-          }
-
-          if (data.route_to) {
-            DiscourseURL.routeTo(data.route_to);
-          }
-
+        .then(() => {
           this.setProperties({
             saved: true,
             updateExistingUsers: null,
@@ -66,7 +46,21 @@ export default Component.extend({
             this.afterSave();
           }
         })
-        .catch(popupAjaxError)
+        .catch((error) => {
+          const json = error.jqXHR.responseJSON;
+          if (error.jqXHR.status === 422 && json.user_count) {
+            const controller = showModal("group-default-notifications", {
+              model: { count: json.user_count },
+            });
+
+            controller.set("onClose", () => {
+              this.updateExistingUsers = controller.updateExistingUsers;
+              this.send("save");
+            });
+          } else {
+            popupAjaxError(error);
+          }
+        })
         .finally(() => this.set("saving", false));
     },
   },
diff --git a/app/assets/javascripts/discourse/app/lib/ajax.js b/app/assets/javascripts/discourse/app/lib/ajax.js
index d3591a5ef92..4ec61986c91 100644
--- a/app/assets/javascripts/discourse/app/lib/ajax.js
+++ b/app/assets/javascripts/discourse/app/lib/ajax.js
@@ -29,14 +29,9 @@ export function handleLogoff(xhr) {
   }
 }
 
-function handleRedirect(data) {
-  if (
-    data &&
-    data.getResponseHeader &&
-    data.getResponseHeader("Discourse-Xhr-Redirect")
-  ) {
-    window.location.replace(data.responseText);
-    window.location.reload();
+function handleRedirect(xhr) {
+  if (xhr && xhr.getResponseHeader("Discourse-Xhr-Redirect")) {
+    window.location = xhr.responseText;
   }
 }
 
@@ -99,7 +94,7 @@ export function ajax() {
     }
 
     args.success = (data, textStatus, xhr) => {
-      handleRedirect(data);
+      handleRedirect(xhr);
       handleLogoff(xhr);
 
       run(() => {
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 97c8f721519..36e4a4394f3 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -260,7 +260,7 @@ class ApplicationController < ActionController::Base
     render json: { error: I18n.t(e.error_translation_key) }, status: e.status_code
   end
 
-  def redirect_with_client_support(url, options)
+  def redirect_with_client_support(url, options = {})
     if request.xhr?
       response.headers['Discourse-Xhr-Redirect'] = 'true'
       render plain: url
diff --git a/app/controllers/groups_controller.rb b/app/controllers/groups_controller.rb
index 153790cfbb7..a5ad225ddb7 100644
--- a/app/controllers/groups_controller.rb
+++ b/app/controllers/groups_controller.rb
@@ -150,38 +150,32 @@ class GroupsController < ApplicationController
 
   def update
     group = Group.find(params[:id])
-    guardian.ensure_can_edit!(group) unless guardian.can_admin_group?(group)
+    guardian.ensure_can_edit!(group) if !guardian.can_admin_group?(group)
 
-    params_with_permitted = group_params(automatic: group.automatic)
-    clear_disabled_email_settings(group, params_with_permitted)
+    group_attributes = group_params(automatic: group.automatic)
+    reset_group_email_settings_if_disabled!(group, group_attributes)
 
     categories, tags = []
     if !group.automatic || current_user.admin
-      notification_level, categories, tags = user_default_notifications(group, params_with_permitted)
+      notification_level, categories, tags = user_default_notifications(group, group_attributes)
 
       if params[:update_existing_users].blank?
         user_count = count_existing_users(group.group_users, notification_level, categories, tags)
-
-        if user_count > 0
-          render json: { user_count: user_count }
-          return
-        end
+        return render status: 422, json: { user_count: user_count, errors: [I18n.t('invalid_params', message: :update_existing_users)] } if user_count > 0
       end
     end
 
-    if group.update(params_with_permitted)
+    if group.update(group_attributes)
       GroupActionLogger.new(current_user, group).log_change_group_settings
       group.record_email_setting_changes!(current_user)
       group.expire_imap_mailbox_cache
       update_existing_users(group.group_users, notification_level, categories, tags) if params[:update_existing_users] == "true"
       AdminDashboardData.clear_found_problem("group_#{group.id}_email_credentials")
 
-      if guardian.can_see?(group)
-        render json: success_json
-      else
-        # They can no longer see the group after changing permissions
-        render json: { route_to: '/g' }
-      end
+      # Redirect user to groups index page if they can no longer see the group
+      return redirect_with_client_support groups_path if !guardian.can_see?(group)
+
+      render json: success_json
     else
       render_json_error(group)
     end
@@ -658,87 +652,74 @@ class GroupsController < ApplicationController
   end
 
   def group_params(automatic: false)
-    permitted_params =
-      if automatic
-        %i{
-          visibility_level
-          mentionable_level
-          messageable_level
-          default_notification_level
-          bio_raw
-          flair_icon
-          flair_upload_id
-          flair_bg_color
-          flair_color
-        }
-      else
-        default_params = %i{
-          mentionable_level
-          messageable_level
-          title
-          flair_icon
-          flair_upload_id
-          flair_bg_color
-          flair_color
-          bio_raw
-          public_admission
-          public_exit
-          allow_membership_requests
-          full_name
-          default_notification_level
-          membership_request_template
-        }
+    attributes = %i{
+      bio_raw
+      default_notification_level
+      messageable_level
+      mentionable_level
+      flair_bg_color
+      flair_color
+      flair_icon
+      flair_upload_id
+    }
 
-        if current_user.staff?
-          default_params.push(*[
-            :incoming_email,
-            :smtp_server,
-            :smtp_port,
-            :smtp_ssl,
-            :smtp_enabled,
-            :smtp_updated_by,
-            :smtp_updated_at,
-            :imap_server,
-            :imap_port,
-            :imap_ssl,
-            :imap_mailbox_name,
-            :imap_enabled,
-            :imap_updated_by,
-            :imap_updated_at,
-            :email_username,
-            :email_password,
-            :email_from_alias,
-            :primary_group,
-            :visibility_level,
-            :members_visibility_level,
-            :name,
-            :grant_trust_level,
-            :automatic_membership_email_domains,
-            :publish_read_state,
-            :allow_unknown_sender_topic_replies
-          ])
+    if automatic
+      attributes.push(:visibility_level)
+    else
+      attributes.push(
+        :title,
+        :allow_membership_requests,
+        :full_name,
+        :public_exit,
+        :public_admission,
+        :membership_request_template
+      )
+    end
 
-          custom_fields = DiscoursePluginRegistry.editable_group_custom_fields
-          default_params << { custom_fields: custom_fields } unless custom_fields.blank?
-        end
+    if !automatic && current_user.staff?
+      attributes.push(
+        :incoming_email,
+        :smtp_server,
+        :smtp_port,
+        :smtp_ssl,
+        :smtp_enabled,
+        :smtp_updated_by,
+        :smtp_updated_at,
+        :imap_server,
+        :imap_port,
+        :imap_ssl,
+        :imap_mailbox_name,
+        :imap_enabled,
+        :imap_updated_by,
+        :imap_updated_at,
+        :email_username,
+        :email_password,
+        :email_from_alias,
+        :primary_group,
+        :visibility_level,
+        :members_visibility_level,
+        :name,
+        :grant_trust_level,
+        :automatic_membership_email_domains,
+        :publish_read_state,
+        :allow_unknown_sender_topic_replies
+      )
 
-        default_params
-      end
+      custom_fields = DiscoursePluginRegistry.editable_group_custom_fields
+      attributes << { custom_fields: custom_fields } if custom_fields.present?
+    end
 
     if !automatic || current_user.admin
       [:muted, :regular, :tracking, :watching, :watching_first_post].each do |level|
-        permitted_params << { "#{level}_category_ids" => [] }
-        permitted_params << { "#{level}_tags" => [] }
+        attributes << { "#{level}_category_ids" => [] }
+        attributes << { "#{level}_tags" => [] }
       end
     end
 
-    if guardian.can_associate_groups?
-      permitted_params << { associated_group_ids: [] }
-    end
+    attributes << { associated_group_ids: [] } if guardian.can_associate_groups?
+    attributes.concat(DiscoursePluginRegistry.group_params)
 
-    permitted_params = permitted_params | DiscoursePluginRegistry.group_params
-
-    params.require(:group).permit(*permitted_params)
+    params.require(:group).permit(*attributes)
   end
 
   def find_group(param_name, ensure_can_see: true)
@@ -767,23 +748,23 @@ class GroupsController < ApplicationController
     users
   end
 
-  def clear_disabled_email_settings(group, params_with_permitted)
-    should_clear_imap = group.imap_enabled && params_with_permitted.key?(:imap_enabled) && params_with_permitted[:imap_enabled] == "false"
-    should_clear_smtp = group.smtp_enabled && params_with_permitted.key?(:smtp_enabled) && params_with_permitted[:smtp_enabled] == "false"
+  def reset_group_email_settings_if_disabled!(group, attributes)
+    should_clear_imap = group.imap_enabled && attributes[:imap_enabled] == "false"
+    should_clear_smtp = group.smtp_enabled && attributes[:smtp_enabled] == "false"
 
     if should_clear_imap || should_clear_smtp
-      params_with_permitted[:imap_server] = nil
-      params_with_permitted[:imap_ssl] = false
-      params_with_permitted[:imap_port] = nil
-      params_with_permitted[:imap_mailbox_name] = ""
+      attributes[:imap_server] = nil
+      attributes[:imap_ssl] = false
+      attributes[:imap_port] = nil
+      attributes[:imap_mailbox_name] = ""
     end
 
     if should_clear_smtp
-      params_with_permitted[:smtp_server] = nil
-      params_with_permitted[:smtp_ssl] = false
-      params_with_permitted[:smtp_port] = nil
-      params_with_permitted[:email_username] = nil
-      params_with_permitted[:email_password] = nil
+      attributes[:smtp_server] = nil
+      attributes[:smtp_ssl] = false
+      attributes[:smtp_port] = nil
+      attributes[:email_username] = nil
+      attributes[:email_password] = nil
     end
   end
 
diff --git a/spec/requests/groups_controller_spec.rb b/spec/requests/groups_controller_spec.rb
index fd29c6741fd..de23c58a79e 100644
--- a/spec/requests/groups_controller_spec.rb
+++ b/spec/requests/groups_controller_spec.rb
@@ -904,14 +904,12 @@ describe GroupsController do
             }
           }
 
-          expect(response.status).to eq(200)
-
+          expect(response.status).to eq(422)
+          expect(response.parsed_body["user_count"]).to eq(group.group_users.count)
+          expect(response.parsed_body["errors"].first).to include("update_existing_users")
           expect(group_user1.reload.notification_level).to eq(NotificationLevels.all[:watching])
           expect(group_user2.reload.notification_level).to eq(NotificationLevels.all[:watching])
 
-          group_users = group.group_users
-          expect(response.parsed_body["user_count"]).to eq(group_users.count)
-
           group_user1.update!(notification_level: NotificationLevels.all[:regular])
 
           put "/groups/#{group.id}.json", params: {
@@ -920,7 +918,7 @@ describe GroupsController do
             }
           }
 
-          expect(response.status).to eq(200)
+          expect(response.status).to eq(422)
           expect(response.parsed_body["user_count"]).to eq(group.group_users.count - 1)
           expect(group_user1.reload.notification_level).to eq(NotificationLevels.all[:regular])
           expect(group_user2.reload.notification_level).to eq(NotificationLevels.all[:watching])
@@ -973,7 +971,7 @@ describe GroupsController do
             }
           }
 
-          expect(response.status).to eq(200)
+          expect(response.status).to eq(422)
           expect(response.parsed_body["user_count"]).to eq(group.group_users.count - 1)
 
           put "/groups/#{group.id}.json", params: {