https://livehelpbook.com/unlicensed-product/ Quick Steps for Microsoft Office Unlicensed Product and Activation Error The Unlicensed Product error occurs when Microsoft Office detects that the installation is not associated with a valid license or subscription. This Office 2021/2019 Unlicensed Product Error can happen due to various reasons, such as an expired trial period, a mismatched license key, or problems with the activation process.