Add tech tree hints to contracts in carrer mode

I tried several times the "Satellite Mission" contract and followed the hints in the description text. I put the CubeSat besides an engine, below the Nose cone and tried to stuff it into a dedicated interstage. The interstage option threw an error.
The other options showed a tick at the CubeSat option before lunch, but during fight it disappeard.
Than I downloaded a rocket from your website and figured out that it had two additional fairing parts.
I guess these parts are necesary to achive the mission.
I suggest that you cant't accept a contract when you have not unlocked the necesary part in the tech tree.
Also add the tech tree part into the mission requirements.
I might be wrong, but can it happen that you unlock the wrong options in the tech tree and than run out of tech points and can't unlock the necesary parts for the next missions?