Every now and then we get a call from end users that they cannot login at Microsoft Teams and they get an error message “The request is not properly formatted” and “The parameter ‘login_hint’ is duplicated.“, especially after changing the user password. The error message is (partly in Dutch) shown in the following screenshot:
This error message is recurring, so it’s not possible to logon anymore. It looks like there’s something stored in a cache related to the user’s old credentials. To resolve this, you can follow these steps:
- Exit the Teams client, and make sure Outlook is also closed since Outlook can have open add-ins related to teams.
- Go to the directory C:\Users\<username>\Appdata\Microsoft\Teams (shown below) and delete all files and directories found there. If any files cannot be deleted, most likely Outlook is still locking files.
When all files are deleted you can start the Teams client again and it should logon successfully.