I'm suspicious about your "first time in many years". What does that mean exactly? A plausible scenario that I could come up with: - You had installed sync bef

I'm suspicious about your "first time in many years". What does that mean exactly? A plausible scenario that I could come up with: - You had installed sync before but uninstalled it. - You started syncing again on the same location as previously. - There was some leftover sync state after the uninstall that was not interpreted correctly by the new version of sync, or had been corrupt. As a result, it was determined that your local files are up to date and cloud files out of sync, which triggered the mass deletion. Bi-directional sync can be nasty...