Previously Working Engines "Flamed-Out"

[ThomJ]

I updated and resumed my previous save game with no issue, took control of one of my ore hauling ships just before it entered Minmus's SOI, landed it at my mining base and docked it to refuel and load ore, all with both engines functioning properly. After I undocked, I hit the throttle to depart and only one of my two engines fired. The one engine that didn't fire said it was "Oxidizer Deprived", despite the fuel tanks being full and it working just minutes earlier. It got even stranger when I re-docked, thinking there was a glitch that caused engines to not receive oxidizer when they dock with something(???) I undocked the second time, literally changing nothing and now my other engine (that had just worked seconds before) was also bricked with the same issue. The engine icons in the staging GUI also seem to indicate that there is no liquid fuel available either so I suspect that this is a fuel transfer issue through parts, but then why would both engines be working before docking, and then still one after the first docking?? Has anyone else encountered this issue with KSP 1.9? Should also mention I'm only running one mod (Kerbal Alarm Clock)

I've included an image of the of the problem

https://steamcommunity.com/sharedfiles/filedetails/?id=1999001210

[Yuccasu]

There is no fuel line from the main tank to the side tanks. Check your settings:
Game difficulty -> Advanced -> Resource transfer obeys crossfeed rules

[ThomJ]

No dice, I enabled that setting and it still doesn't seem to feed properly. Although curiously enough, when I dock with the base the engine on the side that is docked is able to run off the fuel from the storage tank even though it's going through the exact same parts as the on-board fuel tank does. This really seems like an issue with fuel not being able to be drawn from the main tank despite the fact that I can still move fuel in and out of the tank no problem

[Razamanaz]

Are you sure you don't have the fuel flow priorities messed up in the initial build?

[ThomJ]

I didn't think I did, I thought fuel priorities only affected which tanks get drained first, not whether or not they drain at all. This seems like an isolated issue though so I guess I'll just bite the bullet and send up another hauler ¯\_(ツ)_/¯

[krazy1]

Me too... I had a lander with one LV-N that worked fine and docked it to a klaw attached to a orbiting station. Transferred fuel to the lander tanks, came back later, undocked and... no throttle. the engine RMB menu says there's no fuel. It worked before and the tanks are full! So I just spawned a new copy: put a copy of the ship on the launch pad, use ALT-F12 > cheats > set orbit> rendezvous (name of my station in the list). New lander works fine again. I lost the money for the new lander though. Just another example of how buggy KSP is! It's been out for 5+ years and there's still garbage like this happening. boo...