Did you test the end part and black screen in German (same language of the devs)?
Maybe the bug is somewhere in the Eng files only (e.g. with typos in the used tags like </</Text> instead of </Text>)?

In this case you could fix it by yourself since the translation files are simple XML editable files

This bug is definitely not solved. At least not for the English version. No credits at the end and several lines of dialogue throughout the game are missing. It's a shame because the rest of the game seemed pretty polished. I was able to make it through the game without a walkthrough, but missing spoken dialogue resulted in a few times feeling that my game may have been bugged prohibiting me from solving it naturally. What gives?

Just a heads up, the game received the long awaited update/fix yesterday.