If you are getting this error message when opening:
The 'SqlSourceControlPackage' package did not load correctly.
The problem may have been caused by a configuration change or by the installation of another extension. You can get more information by examining the file:
This is caused by an incompatibility in having SSMS's object explorer on the right side of the screen.
To resolve this error, please take the following steps:
1 - Close SSMS and uninstall SQL Source Control
2 - In SSMS, either move Object Explorer to the left (default position) or select "Reset Window Layout" on the Window menu
3 - Re-install SQL Source Control
4 - SSMS should now start correctly and you should have SQL Source Control installed