RTC DS3231 does not loop after initializing - arduino

Question

I'm trying to use the RTC DS3231 - but it does not loop after Initializing in void setup(). I only tried the example codes so far:
/*
DS3231: Real-Time Clock. Date Format
Read more: www.jarzebski.pl/arduino/komponenty/zegar-czasu-rzeczywistego-rtc-ds3231.html
GIT: https://github.com/jarzebski/Arduino-DS3231
Web: http://www.jarzebski.pl
(c) 2014 by Korneliusz Jarzebski
*/
#include <Wire.h>
#include <DS3231.h>
DS3231 clock;
RTCDateTime dt;
void setup()
{
Serial.begin(9600);
// Initialize DS3231
Serial.println("Initialize DS3231");;
clock.begin();
// Set sketch compiling time
clock.setDateTime(__DATE__, __TIME__);
// Set from UNIX timestamp
// clock.setDateTime(1397408400);
// Manual (YYYY, MM, DD, HH, II, SS
// clock.setDateTime(2014, 4, 13, 19, 21, 00);
}
void loop()
{
dt = clock.getDateTime();
Serial.print("Long number format: ");
Serial.println(clock.dateFormat("d-m-Y H:i:s", dt));
Serial.print("Long format with month name: ");
Serial.println(clock.dateFormat("d F Y H:i:s", dt));
Serial.print("Short format witch 12h mode: ");
Serial.println(clock.dateFormat("jS M y, h:ia", dt));
Serial.print("Today is: ");
Serial.print(clock.dateFormat("l, z", dt));
Serial.println(" days of the year.");
Serial.print("Actual month has: ");
Serial.print(clock.dateFormat("t", dt));
Serial.println(" days.");
Serial.print("Unixtime: ");
Serial.println(clock.dateFormat("U", dt));
Serial.println();
delay(1000);
}
Output looks like this:
10:15:16.623 -> Initialize DS3231
Does that mean it doesn't work at all? Or that it doesn't continue to loop after calling void setup?
Any help would be appreciated, that can't be that much of a problem..

Answer 1

Insert
Wire.begin();
before the clock initializes
void setup()
{
Serial.begin(9600);
Wire.begin();
// Initialize DS3231
Serial.println("Initialize DS3231");;
clock.begin();
.
.
.