So when testing the update yesterday i started a new game. new save, to be sure everything works fine and doesnt interfear with old data. it included a side-seeing in the tutorial because it couldnt hurt. guess that was wrong.
After the first small rocket ( later on the upper stage ) i was supposed to install " 3 medium fuel tanks", so i replaced the 2 small ones for a medium one on the second stage and added 3 more on the first stage then. the game didnt know that to do with that and didnt continue when i installed the powerful first stage engine.
from there on i wasnt able to progress and had to quit the tutorial.
i hope that was helpfull, i could at least recreate it each time ( tried it 3 times in total before giving up on the tutorial )