wdContext cannot be resolved

Hi,

I am facing very strange problem in my NWDS. I had created a DC and it was working fine but suddenly it started giving me problem as "wdContext cannot be resolved" rest everything is fine i.e. it is reognizing wdControllerAPI, wdComponentAPI. Only problem is coming for "wdContext" and "wdThis" It is coming in all the Views and Controllers. Guys I am stuck and I am not able to trace out why it is coming.

Please help me out..

Its really urgent.

Thanxs in advance