in one mission only 50 photos are capured by phantom 4pro so what are the solution for that error??

Well... We can't help you much here without more information.

How many were supposed to be taken?

What does the log file say when you look at it with AirData?

Were you using Active Connect or Connectionless mapping?

What did your RC signals look like?

If you need help with this email us your CSV log file out of the File Manager screen and we can give it a look. Or you can look at it in AirData which is what we are going to do with it.