This article is to explain and solve the following error message:
The uploaded template is transformation enabled, but the existing one is not.
This error happens when you try to replace an old document that was originally created with the old plugin configuration with a new document that has been created with, or uses, the new Template Designer features.
We prevent the replacement of such documents to avoid ending up with broken or corrupted documents.
Instead of 'replacing' an existing document template, delete the old one, and then upload the new one.