Can't close trader with my demo account

For sometime I have being having issues with my account, anytime I want to close trade it keep telling me invalid parameter. What is the possible problem

Did you use your broker helpdesk to ask the question?

Invalid parameter usually comes up on your ticket, but shouldn’t affect closing a trade, it’s normally telling you that you’ve entered an incorrect price in the S/L or T/P, for example you are trying to place the S/L price in T/P or visa versa, or you’ve got the decimal placing wrong.

Well, it could have happened once.
But if it happens all the time - it’s a pattern, a sad pattern…

Oh, you definitely need to change your brokerage company if you are constantly facing such problems.