I have a situation in here and I would appreciate your help
I had an offer from a Berlin startup company and after they mailed me the signed contract I have gone to the german embassy and applied for a blue card visa
After my visa got approved the company had some trouble with there funding and we will end up canceling the contract 
The question is if I could get another offer in germany would I be able to apply for a blue card with my current visa (as the company name is printed on it) or would I have to issue a new blue card visa for the new contract from the german embassy again?

Is there any legal actions or paper work that should be done in my current case?

Any Help??

Hi,
this is no legal advice! 

If you are already in Germany and you can find a new job, it is just like a normal employer change, which we discussed here very often.

If you are still in your home country, I am not sure if it is correct to travel with this visa although you know that the employment will not come into effect. But on the other hand.. I guess nobody will ask you since when you knew this. It is up to you. No risk no success ;-

Good luck
Detlef