FIX: show proper message on invite error

app/assets/javascripts/discourse/controllers/invite.js.es6

@@ -149,6 +149,7 @@ export default Ember.Controller.extend(ModalFunctionality, {
 
     createInvite() {
       const Invite = require('discourse/models/invite').default;
+      const self = this;
 
       if (this.get('disabled')) { return; }
 
@@ -168,11 +169,19 @@ export default Ember.Controller.extend(ModalFunctionality, {
               } else if (this.get('isMessage') && result && result.user) {
                 this.get('model.details.allowed_users').pushObject(result.user);
               }
-            }).catch(() => model.setProperties({ saving: false, error: true }));
+            }).catch(function(e) {
+              if (e.jqXHR.responseJSON && e.jqXHR.responseJSON.errors) {
+                self.set("errorMessage", e.jqXHR.responseJSON.errors[0]);
+              } else {
+                self.set("errorMessage", self.get('isMessage') ? I18n.t('topic.invite_private.error') : I18n.t('topic.invite_reply.error'));
+              }
+              model.setProperties({ saving: false, error: true })
+            });
     },
 
     generateInvitelink() {
       const Invite = require('discourse/models/invite').default;
+      const self = this;
 
       if (this.get('disabled')) { return; }
 
@@ -193,7 +202,14 @@ export default Ember.Controller.extend(ModalFunctionality, {
                 userInvitedController.set('model', invite_model);
                 userInvitedController.set('totalInvites', invite_model.invites.length);
               });
-            }).catch(() => model.setProperties({ saving: false, error: true }));
+            }).catch(function(e) {
+              if (e.jqXHR.responseJSON && e.jqXHR.responseJSON.errors) {
+                self.set("errorMessage", e.jqXHR.responseJSON.errors[0]);
+              } else {
+                self.set("errorMessage", self.get('isMessage') ? I18n.t('topic.invite_private.error') : I18n.t('topic.invite_reply.error'));
+              }
+              model.setProperties({ saving: false, error: true })
+            });
     }
   }
 

app/controllers/invites_controller.rb

@@ -41,11 +41,15 @@ class InvitesController < ApplicationController
       guardian.ensure_can_send_multiple_invites!(current_user)
     end
 
+    begin
       if Invite.invite_by_email(params[:email], current_user, _topic=nil,  group_ids)
         render json: success_json
       else
         render json: failed_json, status: 422
       end
+    rescue => e
+      render json: {errors: [e.message]}, status: 422
+    end
   end
 
   def create_invite_link
@@ -59,12 +63,16 @@ class InvitesController < ApplicationController
       guardian.ensure_can_send_multiple_invites!(current_user)
     end
 
+    begin
       # generate invite link
       if invite_link = Invite.generate_invite_link(params[:email], current_user, topic, group_ids)
         render_json_dump(invite_link)
       else
         render json: failed_json, status: 422
       end
+    rescue => e
+      render json: {errors: [e.message]}, status: 422
+    end
   end
 
   def create_disposable_invite

app/controllers/topics_controller.rb

@@ -326,6 +326,7 @@ class TopicsController < ApplicationController
     group_ids = Group.lookup_group_ids(params)
     guardian.ensure_can_invite_to!(topic,group_ids)
 
+    begin
       if topic.invite(current_user, username_or_email, group_ids)
         user = User.find_by_username_or_email(username_or_email)
         if user
@@ -336,6 +337,9 @@ class TopicsController < ApplicationController
       else
         render json: failed_json, status: 422
       end
+    rescue => e
+      render json: {errors: [e.message]}, status: 422
+    end
   end
 
   def set_notifications