Make sure you do not have another machine trying to sync data.
Try Repair first (Repair creates an Archive folder in c:\users\%username%\OneDrive for Business Archive folder. Then it attempts to fix the issues). Always try this first!
- Go to your tray (bottom right hand corner) and right click on your cloud and say "Repair".
If that does not work (i.e. if your sync issues do not go away), Stop Syncing and follow this process:
- Go to the OneDrive cloud in the tray (bottom right hand corner - see above)
- Right click and say Stop Syncing folder (it will give you a warning about permanently stopping this). That is ok.
- Go to c:\users\%username%\libraryname
- Rename the folder to libraryname_old. This will preserve the old data.
- Shut down any Microsoft products (Outlook, Word, Excel, etc.)
- Start Task Manager (Ctrl+Alt+Del)
- End the following processes: groove.exe, msosync.exe
- Check to make sure you have Hidden Files/Folders turned on by going to "This PC" and selecting the View tab. Check the box for "Hidden Items".
- Go to c:\users\%username%\AppData\Local\Microsoft\Office\SPW - delete everything in here. Close the window.
- Go to c:\users\%username%\AppData\Local\Microsoft\Office\15.0\OfficeFileCache - delete everything in here. Close the window.
- Restart your workstation.
- If the sync process does not start automatically, open a browser and go to https://portal.office.com and select OneDrive.
- Click on Sync and let it create a new sync folder
If there are files missing, you will have to go to your _old folder and copy the files to your new sync area.