Lack of thrust when stack separates

[EmanonP]

This worked with the last version, but for some reason, its not working now.

I built my lander, put a rocket on it to get me from Kerbin orbit to Mun orbit.

I then attached my standard lifter with stack separator, and the nifty "make it look nice" shroud covers my lander engine....

I'm now in Kerbin orbit, and about to separate the last lifter tank and engine from my lander unit.....

What happens next is driving me crazy. The shroud doesn't disappear, and when I fire up the engine to get moving, I get absolutely nothing for acceleration. I've tried every engine I can, and still

no acceleration.

Have I suffered a total brain fart, and have I put the stack separator on incorrectly? Did I miss something with the new update that changed how things uncouple?

If I drop the engine from the lander, the 8 small engines on the actual lander fire just fine, and have plenty of thrust.

What am I doing wrong!?!

Edited August 1, 2013 by EmanonP

[painking]

Check your flight log and see if there's anything that broke along the way up. Also try jettisoning the side fairings individually by right clicking the engine and selecting the jettison option. Also try a different engine and see if that changes anything.

[Supernovy]

You put the decoupler on upside down! When rocket exhaust is blocked by a part, it produces no thrust.

The red arrows on the side of them point towards the place they detach from, for most purposes this means they should point toward the command pod.

[dlmarti]

The separator is upside down.

<EDIT>

Got ninja'd

[EmanonP]

Thanks. I wondered if that was the case, but I thought the arrows pointed towards the direction the force of the "bang" would occur when I triggered it. I thought I was in fact "blowing" the lower unit away from my lander, thereby

avoiding damaging the engine above the separator.

[capi3101]

Supernovy and dlmarti are right; that decoupler is most certainly on upside down. Easiest way to tell aside from the arrows? The fact that it's not attached to that last booster stage when you do decouple it.

[Skorpychan]

Nope. They don't damage things above them, just separate off and blast 'down', by default, as seen in the VAB.

Don't feel so bad; I have a rover on Duna suffering from a similar design flaw, and lugging around extra weight because of it. And with a girder on the bottom because I forgot to add a decoupler to it AT ALL.