HERE IS ULTIMATE TRICK TO SOLVE MCENT "YOU ARE NOT ELIGIBLE FOR THIS OFFER" ERROR IN MOBILE AND IN BLUE STACKS.
You may noticed that this error is showing from past few months after mcent updated their app. in new version of Mcent app, they added some security, so Mcent app detects that you are using Emulators & it gives not eligible error which looks like – "you are not eligible for this offer", so without waste more time, talk about the solution.
Tip - Login to Your Account and Complete any Offer - "Try Amazon".