[loneranger_11x]

Impressive achievement and more power to them. But does anyone else find the use of the word "showstopper" peculiar here. In management-speak, showstopper usually means - "There are issues. But we will live with them today. Hopefully fix them tomorrow before anyone notices"

[defphysics]

Actually, what you're describing sounds like something you'd refer to as "not a showstopper". To me, a "showstopper" is something that stops the show: that can't be ignored or "fixed later".

[hamburglar]

Yes. “We were planning to launch tomorrow but someone found a showstopper so we are on a day-for-day slip” is how I’d use it in a sentence.

[throwaway316943]

It originally referred to a performance that was so good that the show had to be stopped while they waited for overwhelming applause to die out. It can be used in a positive sense.