Android : Android: Google Map Null pointer exception error on Action bar button(Map Button)

I'm developing simple Map application. I used action bar. I have added Map button on action bar. When users click on Map button it will take to Next activity(Map Activity). There will showing Map Activity from sqlite db. i'm getting Null pointer exception error when i click Map Button. but when i used Next activity(Map Activity) as a Main Activity. it works well.

Do you think why i'm getting error on Map Button? Do i need to do something to work when i click map button on action bar to go Next Activity(Map Activity) ?

Welcome all the feedback and advice :)