Welcome to the forum.
That’s not a “standard” failure mode so I don’t think there’s specifically a workaround. In other words, the render failed.
When you say “…Nuendo crashed at the final song of that part…” was there some indication of the crash? Or was it a logical conclusion based on the incorrectly rendered track? Obviously a visual indication would be nice but Nuendo may not know it incorrectly rendered if something happened outside it’s control.
Offline rendering is exceptionally dependable, we and others use it a lot. Yes you’re supposed to listen afterwards but for certain things we do not because it’s that reliable. A few things to look out for -
Is your computer accessing WiFi during Nuendo operation? On a Mac that’s problematic, on Windows sometimes.
Take a look at Activity Monitor or Task Manager and see if there are odd things going on.
Play your original source files, make sure there are no glitches.
If you’re adding additional reverb or delay make sure your final marker is past the trail-off of those effects.
There are certain plugins that are definitely NOT friendly to offline rendering although I think that has improved greatly. I don’t know what those are.