I'm using source tree 3.0.15
When I setup my authentication under options, it says my password authenticates correctly .

However when I do a pull, i get the error below - I'm not sure what the problem is.

I've reinstalled source tree, pointless because the settings are cached. I do not have this problem if I run Git from the command line.
One thing worth noting is that, my username is like firstnamelastname however to log into bitbucket I use my email, since they changed it from usernames to emails.
In source tree it shows my username, however to log into the website I must use my email, I'm not sure whether this is the root of the problem.
Using Git from the command line, I don't get prompted at all, I guess there's some caching happening here too, not sure where it's getting the credentials from?
Here is my git configs
