Prospective supervisor stopped replying me before the application deadline A professor agreed on helping me with applying for a postdoctoral fellowship. 
However, after I wrote the application materials and send to him, he stopped replying to me. It is really just several days before the deadline now. And I started to feel frustrated. I don't know what I have possibly done wrong.
Just thinking that I had already ask my professors for writing recommendations and I had devoted much time in proposing and writing the applications. I really don't want to waste them.
Should I make a phone call to ask is there anything wrong? 
What would you suggest me to do?

Thanks!!
I've been in a very similar situation and did make a phone call, or rather a few. I think you should do the same.

The most likely scenario is that they don't have the deadline very clearly in their head and something else came up. Professors have to deal with multiple things all the time and sometimes things just get very hectic. There's probably nothing wrong, per se.

So I'd place a phone call and for example ask him "I haven't yet received your acceptance letter for the fellowship deadline that's coming up. Did something go wrong with the email, maybe?"

Don't wait too long! If he still has to write the letter, make sure he has enough time to do so.