For example, before this change if you were long 1 contract of NQ and your strategy incorrectly sent 2 exit signals at the exact same time back to back, then both signals would get executed at the same time and they would both try to sell the 1 long contract. Since TradeStation futures don't differentiate between selling to close a long position and selling to open a short position, the 2nd sell order would end up taking you short 1 contract.