Guide with Admob (SDKBox)

Please help me. I am very confuse what i did wrong. I have been encoutering the below issue for the pass 5 hours and is unsure what is the error.

* What went wrong:SDK initialized in 553 ms

A problem occurred configuring project ':AdMobTest'.
> java.lang.NullPointerException (no error message)

Please provide more guidance. I am willing to screen share for this one.

I can’t see the reason from the log

how about take a look at this sample project?