Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello.
Please Try the following:
Check the Activation Troubleshooter:
https://support.office.com/en-us/article/Unlice...
If the above does not works try the following steps:
Resetting Office activation
Open Command Prompt and navigate to the following folder
C:\Program Files (x86)\Microsoft Office\Office15
C:\Program Files\Microsoft Office\Office15
Run cscript ospp.vbs /dstatus
Observe the results and uninstall each product key
cscript ospp.vbs /unpkey:<last 5 chars of product key shown in dstatus>
After the above actions please do the following:
Uninstall:
https://support.office.com/en-us/article/Uninst...
Install:
https://support.office.com/en-us/article/Downlo...
Activate:
https://support.office.com/en-us/article/Activa...
Regards