For Microsoft Office products that are not starting and producing errors like, "Excel didn't start up properly last time, do you want to start up in Safe Mode" or "This product didn't start in safe mode last time, do you want to repair," Microsoft is currently working on a fix. But in the immediate need, there are 4 registry keys that can be deleted to fix the issue.
HKEY_LOCAL_USER\Software\Microsoft\Office\16.0\Common\Licensing\CurrentSkuIdForApp
HKEY_LOCAL_USER\Software\Microsoft\Office\16.0\Common\Experiment
HKEY_LOCAL_USER\Software\Microsoft\Office\16.0\Common\ExperimentEcs
HKEY_LOCAL_USER\Software\Microsoft\Office\16.0\Common\ExperimentTas
Once deleted the products will want to start up in Safe mode one time, and then should start normally after that.