Unfortunately it does not seem to have anything to do with file vault. I turned it off, restarted the computer and the problem persists. In my original message I forgot to mention that back-up files are also affected. So autosave files (.lyx#), emergency files and backup files (.lyx~) all look like binary files and don’t work with LyX.
Regards, Marcus -- lyx-devel mailing list lyx-devel@lists.lyx.org https://lists.lyx.org/mailman/listinfo/lyx-devel