A few months ago we began having issues with Office 2010 deactivating itself. We eventually stumbled across SEP being the cause of the issue and a few days later Symantec posted the following KB: https://support.symantec.com/en_US/article.TECH252193.html.
We made sure the update suggested as the fix in the KB was installed and the problem disappeared entirely until yesterday when it began happening again. The user will log in one day, attempt to open an Office 2010 program and get a 'Microsoft Office Standard 2010 cannot verify the license for this product. You should repair the Office program by using Control Panel.' Uninstalling SEP, restarting the PC and reinstalling SEP fixes the problem every single time. Is anyone else seeing this issue?