Backup to USB used to work fine but at some point I got the problem with EX4 freezing when attaching an USB drive (same WD Red drive I’ve used all the time, also tried another WD Red, same problem). The problem started at the time the 2.11.140 update was released so I suspect that may have caused it. That update was supposed to fix an issue with USB backup but I didn’t have any issues with that at the time, so I suspect the changes it has made to USB backup has broken it on my EX4 instead. AFAIR others reported similar problems at that time.
So I’d like to try to downgrade to 2.11.133 where I know USB backup was working fine to see if I’m right. But where do I download older firmware?