Hi @Phillips, Jonni
According to the error message, the administrator disabled chat permissions for some users. If you want to send messages, contact your administrator to enable messaging policies for these users in Central Administration. If you're already in a group chat, you don't need to add it back. Here are the detailed steps about how to enable chat in the Teams admin center:
1. Sign into Microsoft Teams admin center and navigate to Messaging policies.
2. In Message policies page, your administrator can create a new policy for your account.
3. Make sure to turn on the option Chat so that you can chat with other people. After editing the policy, click Save.
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