Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
I had this same issue in Office 2016 but these 2013 instructions worked, just have to go to a different folder for 2016.
Open a Command Prompt window, and then take one of the following actions:
• If you installed the 64-bit version of Office 2013, move to the following folder: C:\Program Files\Microsoft Office\Office15
• If you installed the 32-bit version of Office 2013, move to the following folder: C:\Program Files (x86)\Microsoft Office\Office15
Display the Current License(s) -Type the following command to display the license status. You will see one active license and one that is in a grace period. Note the last five characters of any and all license keys that display in the output:
cscript ospp.vbs /dstatus
Remove the License that is still in the grace period: .
cscript ospp.vbs /unpkey:<last five characters of product key for grace period install license>
Once the remove commands are successful, restart office programs