What kind of gasket is it ?
Did you put it on something flat and make sure your sheetmetal was flat along the sealing surface ?
I don't know anything about ' ultra black'... I use the GE High RTV Red... but I don't use it wet against the surface of the gasket.... I coat the gasket with it...and let it cure overnight... then put another thin...very thin coat and stick it on... this takes away the possibility some might be pressed into the oil pan and get sucked up to the oil screen....
This procedure also makes it easy to use cork gaskets if they are available ,,which have more compression available for bent sheetmetal... or scratches...any flaws ...
Everything has to be chemically clean... so I wipe down with alcohol last... and until your paper towel comes off clean you just keep doing that... and that is slow because it will be drawing the oil out of the pores of the block... but necessary for sealing sometimes..
Greg