The Maximum Equity Protection has been triggered. When this happens all open orders for that EA will be closed and the EA will be removed from the chart. To correct this go the the EA Properties dialog box and scroll down to the Max Equity Protection line and change the value to a lower amount.
Also I notice you installed the 100K EA on the chart. Is the demo account a 100K account? If not, you can correct the error problem by installing the EA that matches your account size.
Alan,