请问如何 避免这个错误呢？

022-01-20 12:00:58 错误 TypeError: cannot read property ‘length’ of null at stop (FILE:144) at main (FILE:491) 2022-01-20 12:00:58 Futures_OKCoin 错误 Futures_OP 3: 503: {“code”:“50001”,“data”:[],“msg”:"Service temporarily unavailable, please try again later. "}

谢谢