Don't know if I'm doing something wrong, or if this is a bug. I just build my second foxtrot, and I have alenium explosives. But I can't put alenium weapons on this foxtrot. The other has them, but this new one is armed with sidewinders and avalanches, and clicking on the weapon or its label does nothing.
I can switch weapons around on all my other aircraft just fine.
Version: v18 stable.
(EDIT: Specify version)