Hi @Hroch Lukáš ,
Sorry, could you translate the error message into English?
Does anyone else have the same issue in your organization?
In this case, we recommend you try to clean your client cache file and restart your Teams client to see if it works for you. For more details about how to clean cache file, please refer to:
https://www.uvm.edu/it/kb/article/clearing-teams-cache/
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