Word 2017 Please unprotect this document
Recently, I was working on a manuscript in Word 2017 that should contain an Endnote bibliography of citations contained both in itself and also in a supplement document. After some googling I found advice, that this can be achieved using the master-/subdocument feature. There are guides online on how to achieve this exactly, so I am not going into detail there.
In the process of updating or inserting the EndNote bibliography into the master document, I kept getting weird errors such as “Please unprotect this document” or “This part of the document is locked”. Sometimes, Word crashed alltogether. However, none of any of the involved documents was locked and all of them had correct write permissions.
Eventually, I discovered that the problem was that I had “track changes” enabled for one of the subdocuments, but not in the master document. After disabling track changes in all documents it magically started working.