My file suddenly disappears and it shows the error: Folder path missing.
So is it missing?
Yes, the folder is missing. What should I do?
Restore it from backup, then figure out what happened to it. Syncthing doesn’t remove the folder root. That said, there’s a spelling error in the path (“Synthing”); are you sure you’re looking in the right place?
Since it’s your
D:\ drive, is it maybe a USB drive and it somehow got disconnected?