I've been trying to get any version of SourceTree (for Windows) greater than 2.5.5 working on my PC for about a week or two, and in my latest attempt, I deleted my local configuration files and uninstalled SourceTree.
Now, when I start SourceTree, I get the "Log in to you account" dialog, but my Atlassian credentials are not accepted, and I keep getting the "Something went wrong while attempting to validate your credentials" error.
I've also tried using my Google account, but the page never refreshes after prompting me to verify my login on my phone.
I've tried the resolution steps I've found here (add to trusted sites in IE, etc), but all to no avail.