This typically happens on volume-licensed versions of Office that are trying to activate against a local KMS host instead of Microsoft’s public servers.
SOLVED: Office Activation Error 0xc004f074 – "Key Management Service (KMS) is unavailable" 0xc004f074 office activation error
Windows and Office have built-in tools designed to identify and fix communication bugs. Go to > System > Activation . This typically happens on volume-licensed versions of Office