Runtime error nr. 401 - Can't show non-modal form

Hi Tom,
i’ve another error during wxsim runs:
http://i.imgur.com/ZsQBcq4.png
No idea what could it be the problem.
Thanks in advance for your support.
Cheers,

Alessandro

http://discourse.weather-watch.com/p/435317

Thanks Bashy,
it will be hard to find the other process