The Microsoft Office Professional Plus Error is a generic error message, and the cause of this error message can vary.
Restart your computer
One way to resolve the error message is to restart your computer. If you receive the message again, contact your administrator.
Computer’s clock set incorrectly
Another reason that you might receive the generic error message is that your computer’s clock might be set incorrectly. Check your computer’s clock to make sure that it displays the correct time and date, restart your computer, and then try to complete the installation or activation of Office again.