Stun shell can't be produced

[Tigers101]

Bug Description:
The stun shell, an item that can be produced by researchers after reaching a certain research level in weapons systems, engineering, and materials, cannot be produced
Steps to reproduce:
1.Reach the research levels required for stun shell
2.try to produce stun shell and be denied
3.retry, and continue to be denied

[Infernus]

Duplicate.