I speak Bulgarian and English. I can somewhat read Russian, but definitely not fluently.
I've gotten similar reports on other mods. I suspect something about the way Factorio handles custom assets changed, so the game isn't finding its own assets. I'll have to figure out what's going on. The files are still in the archives, it's just the paths have somehow become corrupted.
The game requires "package" declaration to be surrounded by three underscores: Alchemistry. However, it's reading one of those underscores as part of the package name for some odd reason.