Critical crash while trying to manipulate production units

[Yeager]

...without selecting them.

If you don't select an unit which is being produced and you want to manipulate its count the game crashes.
I think this is a typical null pointer exception for the game doesn't know the object to be manipulated.
So the solution would be a try-catch-measure (writing in c#, don't know the equivalent in c, but at least an IF-Statement would do it) to hinder the game in crashing if the user/player didn't select any item/object.

[SpaceWombat]

As far as I remember there was always something selected in my production queue. 
(At least some picture was in the right screen indicating what is selected). Was this at the very beginning of a new mission/base?

Try and catch or first item on the list selected by default should fix it imho.

[Yeager]

Hmm,
cannot reproduce this failure again.
Maybe there are some other aspects leading to the crash.

No, it wasn't at the beginning of a mission.
Just during play, when I wanted to reduce some fragmentary grenade production.