Fix error when installing SourceTree

• Turn off compatibility mode in IE. To do that, open Internet Explorer, go to the Advanced options tab and click on Reset your Internet Explorer Settings
• Check Delete personal settings
• Change your Internet Explorer Security Zone Settings:

1. Open IE, click on the gear
2. Select "Internet Options"
3. Select the "Security" tab
4. Select "Custom Level" for Internet
5. Find "Access data sources across domains" and select "Enable" (make note of what the setting currently is)
6. Try logging into Sourcetree again