Hxcpp runtime error

I have a C++ Haxe program that often crashes. The debugger indicates the crash is due to EXC_BAD_ACCESS (code=1, address=0xd0).

The stack trace is as follows:

// this is the top of the stack
// the line below causes  EXC_BAD_ACCESS
inline  ::Dynamic operator()(const Dynamic &inArg0) { CheckFPtr(); return mPtr->__run(inArg0); }

// this is the frame just below the top
void HttpClientAdapter::onText(const char* line){
HX_STACKFRAME(&_hx_pos_31dfed2f121c5749_150_onText)
HXDLIN( 150)		 ::Dynamic _hx_tmp = this->_onText;
HXDLIN( 150)		_hx_tmp(::String(line)); // this is the active line
}

It appears that inArg0 corresponds to the line string (which is not null) in the onText method.

Can anyone provide insight into this issue?