TaskWindow_Input Error

When calling TaskWindow_Input from a WIMP task I get this error:

Message from Uncaught Exception

Child task must be running before sending input

The child task is a BASIC program which continuously reads key presses and prints them.

The task window starts, and the BASIC program is running. So I thought it would print the data from TaskWindow_Input

Child task must be running before sending input

The TaskWindow module doesn’t contain this error message, so what are you doing to send the message? What language are you in? Are you using a library to do this?

In any case, could the BASIC program have finished without you noticing? Also did you actually start the task yourself, i.e. did you ever send a command *TaskWindow &XXXXXXXX &XXXXXXXX ?