Why my phone can't send messages and receive call??

[Android Central Question]

My phone can't receive call when I open wasup mesenger also..I cannot do screen shoot at my phones??

 

[B. Diddy]

Welcome to Android Central! Which phone? Are you talking about WhatsApp calls, or regular voice calls? For screenshots, are you sure you're pressing and holding Power and Vol Down at exactly the same time? It can be a little tricky to get used to.