When you are using folder redirection inside a windows domain user profile due to GPO, you really really don't use windows folder sync on those... 

If you do, the chances you lose all data in those folders that are active for both are way above average... 

guess what... yes my substitutes here did configure exactly this... 

what happened a few times now? reboot of the machine due to secondary admin logon while the original user was in the background still logged in, installing updates, hitting reboot... 

worst case that happens, folder sync finds an empty redirected folder and remembers to erase everything inside, or mirror a new empty folder... everything that was inside before gone... 

now it's time to pray... 

Jesus saves

Budda does incremental backups...

we do have backups right?