FIX: better error message when trying to approve post for closed/deleted topic

app/controllers/queued_posts_controller.rb

@@ -25,6 +25,7 @@ class QueuedPostsController < ApplicationController
     end
 
     state = params[:queued_post][:state]
+    begin
       if state == 'approved'
         qp.approve!(current_user)
       elsif state == 'rejected'
@@ -33,6 +34,9 @@ class QueuedPostsController < ApplicationController
           UserDestroyer.new(current_user).destroy(qp.user, user_deletion_opts)
         end
       end
+    rescue StandardError => e
+      return render_json_error e.message
+    end
 
     render_serialized(qp, QueuedPostSerializer, root: :queued_posts)
   end

app/models/queued_post.rb

@@ -70,7 +70,7 @@ class QueuedPost < ActiveRecord::Base
       created_post = creator.create
 
       unless created_post && creator.errors.blank?
-        raise StandardError, "Failed to create post #{raw[0..100]} #{creator.errors.full_messages.inspect}"
+        raise StandardError.new(creator.errors.full_messages.join(" "))
       end
 
     end