After running the 10.13.4 update, I have been getting this error (see screenshot attached) along with a “The disk you inserted was not readable by this computer” error about 10-15 seconds afterwards. It doesn’t happen every time but usually 2 of 3 times gives me this error.
I imagine the disk not readable message is from the DMG creation failing but haven’t seen that before when it fails. Been running this same script for the past 2-3 years without fail.
I have not seen this, either. It looks like macOS’s disk image subsystem itself is failing to create the disk image. Does this happen for other source folders, or just FMBackup? Perhaps there are some bad blocks in one of the files in that folder, and so the OS times out when trying to read them.
It happens with different sources as well. But not every time. I can run the exact same source again and it will not timeout the second time. I switched the dmg compression type. I’m going to test it out some more to see what I find. I agree that it looks like something in the macOS update causing it.
I was using the LZFSE dmg setting, hasn’t happened since I switched to bzip2. I’ll post an update when I find out more info.