I seem to be getting this error sometimes when trying to recruit from Earth
Unable to recruit: Cargo bay door malfunction
Always work on the second try though.
Update: actually I think I get this error if I press Enter after inserting a recruitment fee, but not if I click on the Recruit button. I'm not sure though.
Update2: this time I used Enter and it worked fine. Weird.
Also, why does the recruitment cost seem to increase (slightly) the more times I recruit?
Ok I figured this out by myself. Apparently recruitment cost fluctuates a little, and "Unable to recruit: Cargo bay door malfunction" simply means you are recruiting too many people and they can't fit in your cargo. It's a confusing error message.