After upgrading the launchpad my rockets simply fall to the ground

[spaceballs]

I managed to orbit Kerbin with a rocket and then upgraded the launchpad. That added some platform and now the same rocket can't stand upright on it. I can't launch anything, they just fall.

rocket on the pad

3 seconds later it falls

What am I supposed to do? How was it fine sitting on the sand

Edited May 3, 2015 by spaceballs

[spaceballs]

I guess it is some bug with that particular saved vehicle. I've rebuild a rocket from scratch after restarting the game and it works fine.

[Torquemadus]

I've found that my rockets have to be carefully placed in the centre of the pad. If the rocket isn't placed dead centre, it leans slightly to one side.

Positioning the rocket dead centre corrects the problem.

[spaceballs]

OK, I wasn't aware I can control that placement .

[Torquemadus]

There are markings on the floor of the VAB that you can use to align your rocket.

[The Yellow Dart]

Also, if you delete your root part, and reselect it from the parts menu, it will reappear in the exact center.

[Skorpychan]

Have you considered using launch clamps instead?

They also let you save DeltaV by moving the rocket higher up in the VAB.