Hi @Julia Ko ,
Do you have any operations before this issue occurred?
Do you have the same issue in Teams web client?
To exclude the client issue, we firstly recommend you try to clean your Teams client cache file to see if it works for you:
Clear cache by deleting any file in the following folders:
• %appdata%\Microsoft\teams\application cache\cache
• %appdata%\Microsoft\teams\blob_storage
• %appdata%\Microsoft\teams\Cache
• %appdata%\Microsoft\teams\databases
• %appdata%\Microsoft\teams\GPUcache
• %appdata%\Microsoft\teams\IndexedDB
• %appdata%\Microsoft\teams\Local Storage
• %appdata%\Microsoft\teams\tmp
In addition, you can also try to delete this user from your Teams and re-add and assign member roles.
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