This error message appears when you attempt to post an order to sell more shares than was available in your account. To avoid this error, view your Uncommitted Stock Positions first under the TRADE tab followed by the PORTFOLIO function before placing new orders. Always check if you still have pending orders -- remember that a posted order will commit your available shares, and this will be deducted from your uncommitted number of shares. You can post selling of shares of up to that number that is uncommitted only. You must cancel your posted order first to reinstate your uncommitted share balance before attempting to post a new sell order.