On a 5.5.2 site, after making changes on a block to a Default layout the entire site started showing the following error message:

Fatal error: Call to a member function getBlockTypeHandle() on a non-object in /home2/talentpa/public_html/concrete/libraries/block_view_template.php on line 41

I've tried renaming the blocks, tried applying the Plain Yogurt theme and the error won't go away. The Dashboard works fine. My guess is that there is a data issue but I'm not sure how to fix it or where it is coming from. Any suggestions would be greatly appreciated.