You need to do some debugging. I know nothing about your IDE but it's probably capable of printing to a console or a log. Pepper your code with print/log statements so that you can see where it's hanging up.

Do you not see a report of any problems? You should have a way to trace crashes. Find out how to use it. The information it reports can be very cryptic but it may point to the command in your code that caused the crash.

 

That's a wifi error maybe the phone sim needs to be setup it maybe not your code.

 

Wrap each part of your code in try/catch and put breakpoints in all the catch statements. Examine the exception that comes back.

try
{
something()
}
catch(Exception ex)
{
// examine ex here

}