IndexError('index out of bounds',) Why this, on sell or buy orders?

Hi
I had been getting these errors on execution of Sell or Buy Orders.

IndexError(‘index out of bounds’,)

They show up randomly, random symbols, the Orders don’t execute. I have seen them in up bracket orders, mostly and few on regular order types.

I don’t understand the reason of getting them, and why they happen on our system. Can anyone inform the possible reason and how to solve them,so that orders execute.

Thanks.

Could you share your code?