Do you mean when you schedule a Teams meeting, it pops up error message when you click the Meeting Notes button?
According to the error message, it seems about creating a wiki tab on teams. It recommends you check if you assign the SharePoint license to the user correctly.
Moreover, go to Microsoft Teams admin center to check if the app policy restricts some related application.
Someone told that if you have an Office 365 Application that using "https://<tenant>.sharepoint.com", and this causes Microsoft Teams does not work at all. For more details, please refer to this link: https://techcommunity.microsoft.com/t5/microsoft-teams/wiki-and-documents-are-not-working/m-p/55071.