I ran into the following problem last night: if an edit is made to a question file and saved, once the file is re-accessed, the contents of the entire file is deleted. The files still exist, but they are empty.
I first noticed this error when I tried testing new edits. I received the following:
ERROR: This problem file was emptyI have been editing problems for much of the summer and this issue has just arisen. I have a copy of the course as backup.