backend/app/controllers/wiki_pages_controller.rb

@@ -92,7 +92,7 @@ class WikiPagesController < ApplicationController
 
     return head :unprocessable_entity if name.blank? || body.blank?
 
-    tag_name = TagName.find_or_create_by(name:)
+    tag_name = TagName.find_or_create_by!(name:)
     page = WikiPage.new(tag_name:, created_user: current_user, updated_user: current_user)
     if page.save
       message = params[:message].presence