I'm pretty sure this message isn't coming from "Fuel Tweaks" - because I don't have that installed - but since you've been poking around in the plumbing with a digital blowtorch and a fire extinguisher, then you can probably point me to the right OXP.
I'm getting intermittent "out of fuel" radio traffic of the form
11:31:09.361 [LogEvents]: Player got message from Boa Class Cruiser 24018 : Still waiting for [commanderShip_string].
11:31:19.421 [LogEvents]: Player got message from Boa Class Cruiser 24018 : Still waiting for [commanderShip_string].
So, someone's OXP isn't resolving a variable correctly. I've got about 4 OXPs loaded with "fuel" in the title, and I'm not sure who to alert to this bug. Can you point me at the guilty?
oolite.oxp.smivs.ExtraFuelTanks.oxz ; oolite.oxp.Frame.FuelCollector.oxz ; oolite.oxp.Thargoid.MilFuelInj.oxz ; oxp.AndreyBelov.DuplexFuelTank.oxz ;
Hmm, two extra fuel tank OXPs. I should tidy that up.