I just got a new laptop and had previously been using SourceTree on Windows 7 without a problem. However, I cannot make it work on Windows 8.1 - it pops up with a blank dialog and another blank "Welcome" dialog. If I click somewhere within the "Welcome" dialog, it either goes away or reappears depending on where I click, and eventually I get a message saying that Sourcetree "has stopped working". I love the program and want to continue using it. On your homepage you show it running on Windows 8. What's the problem?