Hi @Phumsak Rattiyawong ,
How did you activate the Office? Did you enter the product key or sign in Microsoft account?
Did you activate your Microsoft office package by using KMS script or running an office activator that may have detected in a Microsoft office update?
I suggest you go to File- Account and provide the detail information screenshot about Office, post the screenshot here.
Remove KeyManagementServiceName from registry, open the command prompt as admin then run the following commands:
reg delete "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform" /f /v KeyManagementServiceName
reg delete "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\OfficeSoftwareProtectionPlatform" /f /v KeyManagementServiceName
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