New H1B filing with prior Petition Rejection

my previous employer (A) initiated my H1b for 2014 Cap. But the petition got denied. As per employer A 's policy they neither share the Receipt number nor the Denial reason in case of rejection.

Now my current employer (B) will be filing for my H1b for 2017 cap. But I do not have the earlier denial reason or the receipt number.
What to do? Please suggest.

Is it mandatory to furnish the earlier H1B petition denial reason during a new filing?
What are the impacts on my fresh filing if I do not share the earlier denial details?

Thanking you in advance.

It is not required to provide the old denial reason to new employer.

The only advantage of knowing the denial reason is that in case it is related to you and not employer, it gives you an opportunity to correct it before re-applying. If it was related to employer and you are filing through a different employer, then there is nothing to worry.

Thank you very much Saurabh, I was really worried.