To troubleshoot an issue with deleting a message in a Teams conversation, trying these steps:

1. Check with the Owners or Admins of the Team you're in- if you are not the Owner/Admin, only they have the ability to delete messages.


2. Ensure you are using the latest version of Microsoft Teams.


3. Ensure you are using the most updated web browser version. If possible, switch back and forth between 2 different browsers.


4. Clear your browser history and caches.


5. Restart the Teams client.


6. Reach out to Microsoft Support if none of these steps have worked.