I've created a Sandbox to begin the unfortunately tedious process of migrating to Lightning Knowledge. To do this, Salesforce requires that we merge all existing Knowledge Articles into a single Article Type, and delete all other Article Types. This must be done prior to even being allowed to enable Lightning Knowledge:
Our company were very early adopters of Lightning Communities, and we originally worked with an Implementation Partner who built a lot of custom lightning components for us to drive content on our Community. Unfortunately, most of that content was driven by Knowledge Articles.
I created a new Global Article type for the transition, moved all the articles to that type, and began modifications to 10-12 different controller classes that referenced those types. One by one I managed to delete 8 out of 9 of our old article types after commenting out the related controllers.
I cannot however delete this last one. After commenting out / deleting all of the references to the article type, I'm still left with the following two errors when I try to delete:
The object you're trying to delete is in use on site SITE_NAME_C, which is published.
The object you're trying to delete is in use on site SITE_NAME_C, which is under development.
I've searched and only found one other related post, and that user never got an answer: Cannot delete lightning component
I've been pouring over the Community for hours trying to find any reference to this article type, either in the default setup of the site, or in a component. I've actually started deleting groups of pages and trying again, but have since found nothing. Interestingly, even though there are two separate errors, they both refer to the same site - one of them says the site is Published and the other says its under development. The link to the site is the same on both errors, so its the same site.
This is completely blocking our ability to migrate to Lightning Knowledge, and, by extension, stopping us from migrating our Support teams over to Lightning. Can someone point out something I might be missing?