Hi @fircx,
It looks like one of your redirect URLs might be setup incorrectly. In GitLab can you go to Admin Area -> Applications and see what is under Callback URL for Mattermost? The domain for each callback URL should be your Mattermost domain.
Hi @fircx,
It looks like one of your redirect URLs might be setup incorrectly. In GitLab can you go to Admin Area -> Applications and see what is under Callback URL for Mattermost? The domain for each callback URL should be your Mattermost domain.