Yes this will crash. when you look on the troubleshooting page under "crash" you see that its the third most frequent beginners mistake listed there.
The fix:
Code:
ThisTrade = enterShort(1, myEntryPriceShort, myATR, 0, Spread);
if(ThisTrade) {
MyEntryPrice = myEntryPriceShort; // The script is crashing here. When I quote it there is no crash.
MyTradeSetBreakEven = 0;
}