60 leds and the Adafruit OLED libraries, that uses a lot of ram.
Could you add the freeMemory() function to your sketch: Measuring Memory Usage | Memories of an Arduino | Adafruit Learning System.
Call it for example from the updateDisplay() function.
Can you test your sketch with one led ?
Did you know that OLED displays disturb the I2C bus for others, especially when a 5V Arduino board is used.
Only the Adafruit OLED modules are reliable with a 5V Arduino board.
The first thing in setup() could be printing something.
void setup()
{
Serial.begin(9600); // Starts the serial communications
Serial.println( "The sketch has started");
...
}
That puts the text in the TX buffer. While that is being send to the TX line in a interrupt, the sketch continues. If only a few characters show in the serial monitor, then you know that the sketch has crashed a few milliseconds after the call to Serial.println.