There's no error. The code just stops after you enter the fahrenheit
#include <iostream>
#include <iomanip>
using namespace std;
//function prototypes
void getFahrenheit(int &);
void calcCelsius(int, double &);
void displayCelsius(double);
int main()
{
//declare variables
int fahrenheit = 0;
double celsius = 0.0;
//get input item
getFahrenheit(fahrenheit);
//calculate Celsius
calcCelsius(fahrenheit, celsius);
//display output item
cout << fixed << setprecision(0);
displayCelsius(celsius);
return 0;
} //end of main function
//*****function definitions*****
void getFahrenheit(int &fah)
{
cout << "Enter Degrees in Fahrenheit: ";
cin >> fah;
} //end of getFahrenheit function
void calcCelsius (int fah, double &cel)
{
cel = ((5.0/9.0)* (fah - 32.0));
cin >> cel;
} //end of calcCelsius function
void displayCelsius(double celsius)
{
cout << fixed << setprecision(0);
cout << "Temperature in Celsius is: " << celsius << endl;
}