Passt das? "Investitionshindernis" ginge auch.

I would propose reorganizing the sentence into "Das hemmt den Prozess"

Oder:

Abbruchkriterium
Unüberwindbares Hindernis

Wird sehr oft auch im Projektkontext genutzt, z.B.

The data center cannot upgrade the system software to the new version. This is a show-stopper for our project.

Siehe auch folgende ausfuehrliche Diskussion im Archiv:
  related discussion:showstopper</A

Das könnte sich als Haken erweisen?

Abgeleitet von "die Sache hat einen Haken"

From the OED: "show-stopper: an item (esp. a song or other performance) in a show that wins so much applause as to bring the show to a temporary stop"

This is interesting, because I believe all of the above contributions (calliope, Martin, Mattx, Jochen) are on the right track. That is, Tini's sentence seems to require a translation along the lines of "Hemmnis," "Hemmung," "Haken," etc.

It appears we have before us another example of how clichés evolve, sometimes into their opposite.

For future reference, translators should take note of the expression's original meaning, since it is still used in the original, positive sense.

Oreg's advice, that we reread the previous discussion on showstopper, is very good advice indeed!

"to be a show-stopper" = Furore machen (a performance of great popular appeal) is positive.
The problem lies in "This could". If substantial cash Investment were to be had up front, they would, by inference, have a show-stopper (successful performance) on hand, allbeit with no revenue until 2007.

Admittedly, the speaker might have used the term show-stopper ironically, which, however, is as such in none of my standard dictionaries.

> If substantial cash Investment were to be had up front, they would, by inference, have a show-stopper (successful performance) on hand, albeit with no revenue until 2007.

You have it exactly backwards--they would have no performance at all. The original states:

> Under this scenario, the deal may require substantial cash investment up front, with no revenue until 2007. This could be a show stopper.

Showstopper here means deal-breaker, not great success.

Having to pay a lot of money up front, and getting nothing back for two years means that the deal will never go through in the first place. It's a deal-breaker, because the conditions stop the show before it starts--there will be no deal.

The problem does not lie in 'could', but in the two different, and nearly opposite meanings for 'showstopper'.

@Peter <us> - The modal auxiliary "could" can occur in present and past contrary-to-fact conditions. In conversation, the present contrary- to-fact is often casually used with temporal pointers instead of the past : "I could have danced all night"[but I didn't], "I could dance all night [but I won't]. As a tag-phrase, "This could be a show-stopper," the reference could be to what might have been, but also to what one day might be. In either case a hoped-for show-stopper. As a scenario is involved, modal auxiliaries are to be expected. A sentence like "This will certainly stop the show" would have obviated J.G. Whittier's "For all sad words of tongue or pen, / The saddest are these: "It might have been!" (1854). - in our case, "it could be" and "it could have been."

"Under this scenario, the deal may require substantial cash investment up front, with no revenue until 2007. This could be a show stopper."

I'm not a english native speaker but it seems to me that the "this" in the second sentence would normaly belong to the "with no revenue until 2007" part. So shouldn't show stopper be something not positive.
Wouldn't u say "This could be a show stopper nevertheless" if u mean that the project would be positive despite of the bad revenue situation?

Negative Übersetzungsbeispiele haben wir zwar schon genügend, mir fiel aber grad noch eins ein

Also ich habe es für meinen Text jetzt mit K.O. Kriterium übersetzt, denn das war das was definitiv gemeint war.

Danke für die angeregte Diskussion