This is a plugin for the Kerbal Space Program. It provides several modules and parts to store complete vessels that aren't needed to free CPU of their burden.
Could it be that I should not put a self-propellant vessel with tanks and engines using hydrolox inside a hangar fairing?
The tanks got radiators, but something else was borked - the tanks only got 20% LH2 left as I deployed the vessel from the hangar fairing - about 10 minutes after launch.
(The stages before didn't use LH2)
So I wonder if LH2 tanks are the culprit?
If only probes with RCS are allowed then the purpose of the hangar fairing is getting smaller for me.