I'm finding, after working on a file for a day, that the folder containing the pln file is joined by others with the same file name with a number added, Planname 2.pln...Planname 3.pln...etc.
I store my files on iCloud. I don't know if tis is a factor or do I need to tweak Archicad settings???
Do not store working files on a cloud based service (iCloud, Dropbox etc) you risk corruption, always download to your local server / pc and work from there, only use cloud base file sharing for upload / transfer