The office program shows an unlicensed product message on it if the product is not activated. The program requires an official license key for activation. Here you can find some more issues,
https://www.winchatsupport.com/unlicensed-product/
Here are the Issues of Office License:
Word Unlicensed Product: Firstly, If the product key is used in more than allowed devices, it will show you unlicensed in the other devices. Unlicensed software cannot be used. You cannot edit the word files and save them. The unlicensed error message also appears if the payment is overdue for subscription-based products. Secondly,
What to do if a product shows unlicensed?
You can get a new product key to activate the product on the other computers which show “unlicensed”
https://www.winchatsupport.com/unlicensed-product/