Game breaking bug

[quin456]

Nine out of ten times when I drop empty fuel tanks and start using a less powerful thruster (I have tested this with multiple thrusters) while trying to get into orbit around Kerbal, my thrusters become COMPLETELY useless. They are firing and my fuel is depleting but they have absolutely no effect on my trajectory. I have tried going full throttle retrograde to test this and my speed actually increased slowly due to a lowering phase of my half orbit. I bought the game, but I have tried downloading completely outdated versions in the hopes of avoiding this issue, but to no avail. If I can't get things into orbit around Kerbal I really can't play the game at all. And no I don't just suck at getting into orbit.. I have tested this with nodes more often than not and when I switch engines the Delta V bar thingy just stops going down and the estimated burn time flickers between around 2-10 days. I have also experienced this issue when trying to get out of the muns orbit to return to Kerbal.

Any help would be much appreciated

[diomedea]

What you describe seems what happens when another part is "covering" the engine nozzle (even if you may think is not, KSP is pretty sensitive about that). Covered engines can't exert thrust.

I'd suggest you upload your .craft file and link it here to have it checked.

If the issue is different, could be better to show (with a few screenshots or a video rec) how that shows in game.

[Claw]

Diomedea is right. Generally speaking, the area at the engine nozzle needs to be clear out to about 2 to 3 times the length of the fire plume. That's not an exact number, but works as a pretty good rule of thumb.

If that isn't working for you, it would definitely help if we had either a craft file or some pictures.

Cheers,

-Claw