Thanks for the report — this was a real bug in an earlier version (the output multiplier had no upper bound, so pushing Stardust high enough broke the math into Infinity/NaN).
It's been fixed since: Sector Warp is now capped at +1 Stardust per warp, and the multiplier formula itself is hard-clamped so it can never overflow again, no matter how far it's pushed. If you grab the latest version and still manage to hit Infinity somehow, let me know — I'd genuinely want to see how, since it shouldn't be possible anymore!