I accidentally had a controller file open in two different windows, with different edits. When I went to save the second one, the system correctly recognised the problem and warned me about it. It offered to 'merge' the two files. I chose this option. The merged file had lost all the carriage returns and linefeeds. (I checked with a hex editor and they were completely gone.) So I clicked on 'revert' to go to the previous version. Same problem, so I now had no okay version. As python relies on indentation, this was a horrible mess to sort out.
I just tried to repeat the process on a dummy py file. I was able to reproduce the problem exactly. It is a nasty bug as it seems to corrupt the backup file as well as the live file, strange.. Peter

