My PC was failing to sync new changes in OneDrive for Business. I would save changes to a file locally, then the file's status icon would show "sync pending" but in the OneDrive tray icon it would just say "processing changes..." but didn't list any actual files. When this continued for over an hour, I searched for a resolution and found the suggestion of unlinking and relinking the PC with the problem, so I tried that. When I re-linked it, I chose to use the existing local folder location hoping it wouldn't need to re-download 45GB of files. It seemed to be working from my end, but then my colleagues told me they were getting notices that I was deleting a lot of files in folders that we share. I was obviously not doing this myself. But the pattern I noticed is that the files were all in areas that show as "available when online" on my PC. I suspect that when I relinked my PC, when the sync process saw that these files were not stored locally, it synced that to the cloud as a deletion. My colleagues were able to restore the deleted files, but OneDrive support suggested that I report the bug here.