What it says on the tin. Never run into this one before while using custom styles so I’m not sure where it’s coming from, any ideas? Any string of text, including a blank line, that I apply any custom style to is instantly deleted. I’ve tried doing this from a fresh document to see whether there happens to be anything wrong with the settings of the one I’m trying to work on and actually managed to break a new one that way, by deleting the starting blank line, so suffice it to say this is not a document setting issue.
Click Help - Restart in safe mode - Continue in safe mode, open the document and see if the same issue occurs. If it does please upload a small sample document which shows the problem