I am running Windows 7,and found that suddenly effects is greyed out ever since I updated to Audacity 2.2,2
Would you please help me with this problem.

You are probably in Pause mode rather than Stop - just press the Stop button


I hope that is a typo for 2.1.2.

If it is not a typo, uninstall the bogus Audacity version you have and install Audacity 2.1.2 from http://audacityteam.org/download/windows.