Deleting a Layout that contains Blocks creates orphaned records in the CollectionVersionBlocks table0 0 Browser Info Environment
I can reproduce the issue on a fresh installation of Concrete5 v8.2.1:
I created a new Empty page using the Blank page template. I added a Layout to the Main Area and then added a Content block inside the Layout. After publishing the page and querying the CVB table for the latest version of this page, I can see 2 rows as expected.
Next, I edit the page and Delete the Layout while it still contains the Content block. Now the page shows "Empty Main Area" and I published the changes. Querying the CVB table again for the latest version of my page, I still see 1 row and it has an arHandle value "Main : 50". Since this page no longer has any blocks that I can access in edit mode, I believe this is an issue.