IDETalk, error messages on frame deactivation

After my first attempt at using IDETalk, every attempt to close the frame now results in the error in the attached file.

The message is:

Cannot save project:
Could not instantiate converter: com.thoughtworks.xstream.converters.extended.ThrowableConverter

Every time I deactivate the main IDEA frame, the dialog appears, which is very irritating. I'm obliged to quit IDEA to get rid of the message.

Thanks,
Chris