Why office 365/2019/2021 shows unlicensed product error?

If Office installation failed, the title bar of your Office programs will display office 365 2019/2021 Unlicensed Product or Non-commercial use, and most Office functionality will be blocked in windows 11 and windows 10 Operating system. Similarly, if your membership expires or you choose to cancel it, Your access to Microsoft Office 365/2019/2021 services, apps, and customer information will go through a series of states before being fully turned off or erased. To restore all features of Office program, you’ should fix the problem that is letting activation to fail.