Proposed explanation and solutions for Office C2R 'Your license isn't genuine' banner:

Solution (Known to be perfect):


Install any of the below products:

Activate with KMS:

Experimental solutions: 

The solutions which are currently working but won't work with upcoming updates:

The solutions which are not working for all:

The explanation on how Office is identifying non-genuine KMS license:

To be added...


Updated on 23-May-2021