"License validation error" when a Microsoft 365 administrator tries to disable a Skype for Business Online user
Problem
When a Microsoft 365 administrator tries to disable a Skype for Business Online (formerly Lync Online) user, the administrator receives the following error message:
"License validation error: the action 'Disable-UMMailbox','Identity', can't be performed on the user **<user>**, with license **<license>**
Solution
To resolve this issue, apply the correct license, and then try to disable the user again. For Skype for Business Online, an Exchange Plan 2 license or higher is required.
More Information
This issue occurs because the appropriate license isn't applied to the user. Therefore, the action fails with a license validation error.
To perform any administrative action, a valid Exchange Plan 2 license or higher is required for user enablement or disablement of Skype for Business Online. Microsoft 365 administrators must make sure that the appropriate licensing is in place so that users can use the feature or perform the administrative tasks that are related to the feature.
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