Dart engine not detecting fuel

[DSFX]

It's the strangest thing.  I build my planetary transport ship.  When i got it together in orbit the engines refused to ignite.  The message i get is "Oxidizer Deprived".  I'm using 8 dart engines, they worked on the way up. But after some reconfiguration they don't seem to be detecting the fuel in the tanks.  I've enabled all the cross-feeds and have tanks that support LF and oxidizer.  When i hit F12 and enable unlimited fuel everything works fine.  I'm really stumped here.  The only mod i use is mecjeb.  Does anybody have any idea whats going on here?

 

Thanks,

[Streetwind]

Welcome to the forums

Unfortunately your question is impossible to answer as it is. Someone might guess the answer by pure chance, but that's not really the way it's supposed to go, right?

In order to help you, we need a screenshot of the craft in question. Ideally in sunlight, focused on the engine and tankage section, from a useful angle, close enough to see details. That way, if there is a crossfeed-blocking part in there, people can spot it right away.