WordPress Speed Up Service | WordPress Website Maintenance Packages Reply To: Child Theme. ” Internal Server Error” when creating new pages., by Steve Stern I use the method outlined in the codex to create child themes. If you started modifications on the parent, you should get a clean copy of the parent, figure out what you modified, and make a new child that can be run from an unmodified parent. Reply To: Child Theme. ” Internal Server Error” when creating new pages.