Sometimes Office365 OneDrive folders will end up being corrupted. That might happen when the folder has a large number of files or subfolders.
Here is how to fix it:
- Delete your sync pair
- Rename the folder in Office365 Onedrive (for example rename it to “old_name SAVE”)
- Create a new folder in Onedrive with the same name (i.e., old_name)
- Copy all files and folders from “old_name SAVE” to “old_name”
- Delete “old_name SAVE”