I have a issue with sourcetree remote connection with our GitLab server. Using sourcetree version 3.0.12. I have attache pictures which elaborates the issue.
The Remote button will open the repository's home page on its host server, but it can only do that if the repository has been associated with a remote server, e.g. GitHub.com, GitLab.com, Bitbucket.org or a self hosted instance of GitLab etc.
In order to do that you need an account, Tools/Options/Authentication, for that host server setup in Sourcetree. With that you can then use the Edit button on your 2nd screenshot. That opens a dialog where you can associate the current repository with the host account. Sourcetree is then able to determine the correct URL for the Remote button
This answer helped my to identify ma problem - I have set up multiple remotes, but SourceTree uses not the default remote "origin", but apparently the URL other/second remote configured for this repository. Is there a way I can influence/set the remote URL, which is used when i press this button?