Here's one that happened to me maybe 8 to 10 years ago. I was programing a show on an older
ETC board. I don't remember what model off
hand, but it was a small board with only subs. The show had about 90 cues. When I tried to save the show to disk, the board dumped it's memory, going back to it's default settings, and erased my disk. Fortunately, I had kept pretty good notes on the light cues, and most of them were restores to previous looks, so I spent the next 20 minutes restoring the patch and reprogramming the show. I still had to do a little minor tweaking for the next night's rehearsal, but it all worked out in the end.
Needless to say, I didn't even try saving to disk again until that show was over. When I did try saving again, everything worked just fine. I had never encountered this problem before, and have never encountered it since. That board has since been retired, replaced by an
ETC Express 24/48.