According to your description, I have the following questions to confirm with you:
- Does the Teams web client have the same problem?
- Do other users in your organization have questions?
If you're using the desktop client, please make sure your operating system is up to date and try clearing the cache of the Microsoft Teams desktop client and try to check if this error issue disappears from the Microsoft Teams desktop client on Windows.
Also, I'm noticing a potential issue in Service Health. Users may not be able to upload files or photos from some group chats from the Microsoft Teams desktop and web client. This requires your patience to wait for the next update. Thank you for your understanding and patience!
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