Why is the "New order" option grayed out and cannot be clicked on MT4 / MT5?

If the symbol chosen is not grayed out, ensure the client logged in using the Master Password and not the Investor Password.

The Investor Password is read-only, and using it to login will result in MT4 being in a read-only status.

Check the login credential email for both passwords. For more information on the Investor Password, click here.