Hello Gokhan,
1. Make sure you use SSMSBoost2012 install for SSMS 2012.
2. Try to uninstall SSMSBoost and install it again. You can backup your settings, located at "C:\Users\USERNAME\AppData\Local\Solutions Crew\Ssms2012\SSMSBoostSettings.xml"
3. If it still does not work please post exact versions of SSMS (found in About dialog).