1. Mark sure none of the following processes are running in Windows Task Manager: groove.exe, msosync.exe, msouc.exe, winword.exe, excel.exe, powerpnt.exe.

2. Open the Command Prompt (run as administrator), remove Office file cache and folders by running the commands below:

1) cd %USERPROFILE%\AppData\Local\Microsoft\Office\15.0\
2) rmdir OfficeFileCache /s
3) cd %USERPROFILE%\AppData\Local\Microsoft\Office\
4) rmdir Spw /s

3. If the issue persists after doing this, sometimes Repair Office can be a good solution. Please try to Repair Office from the Control Panel and check to see whether these issues still exist.