What has happened here is while you tried to add or remove a folder from OneDrive, since it is already available somewhere else, the conflict occurs.
The file or folder with the same name already exists on OneDrive
Follow these methods to resolve the The file or folder already exists on OneDrive issue. Make sure to keep a copy of the folder or file in conflict before you proceed.
1] Delete it from the PC
OneDrive maintains a copy of the file or folder on the PC. If you directly delete it, it will also be removed from online and any other synced device. Make a copy of the file or folder on your desktop or anywhere outside the OneDrive folder. Then delete the same copy from OneDrive. It will remove all the copies across the devices. Now that you are sure there are no conflict copies, you can drag and drop the files into the same location. Once it is synced, it will be available on other devices.
2] Remove the file or folder from OneDrive
The second method is to use the online version of OneDrive. Go to OneDrive, sign in with the same Microsoft account which is on the PC. Once inside, locate the folder, and choose to remove it. This will make it disappear from all the locations. Make sure to make a copy of the folder in both methods not to lose any data.
3] Make it unavailable on your PC
OneDrive offers a feature where you can view the folder structure and still don’t download it. If the file is available on your PC, you can choose to keep them online instead of downloading them on your PC. Please navigate to the folder which is under conflict and then right-click on it. Select Free Up Space. OneDrive will remove it from the PC but keep the online version intact. OneDrive conflicts are common, but it is not scary because the data is not lost. The best way to resolve this is to take backup, remove it from OneDrive, and then resync. That way, it will resolve all conflicts. More ways here to fix OneDrive errors on Windows 10.
