Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi , personnally, it appears once a month, I found a fix by killing - using task manager - OfficeClickToRun.exe, then restarting MSOffice application. Can't explain why it suddenly blocked MSOffice, but it works each time.
Which version of Office are you running? Note that Office needs to contact the activation servers about once a month, to confirm the license. Perhaps something happens on your system during that check. Try repairing your installation; see https://support.microsoft.com/en-us/office/repair-an-office-application-7821d4b6-7c1d-4205-aa0e-a6b40c5bb88b.