error after updating the support library

Question

I just updated my libraries when Android 5.0 got lunched today

one of the files that got updated is android-support-v7. after that I kept getting these errors

Answer 1

My solution to a similar error;

1) I installed 21 api with sdk manager.

2) I changed my project's build target to 21. and I changed v7-appcompat library build target to 21.

and finally I think support library projects (v7-appcompat or v7-gridlayout) must be in workingset.