The Zettlr 1.4.3 installer for Windows is only 532 Kilobytes.
It doesn't open an installer and if I unpack it, it only has the the file "Z_\Users\hendrik\Documents\Zettlr\release__uninstaller-nsis-zettlr.exe" in it.
The SHA-256 sum that comes with it is correct for this package, though.

Huh, I didn't see that. Just re-ran the setup and saw that apparently wine is broken. I'll see to running a build asap on another machine!
Release is fixed, the Windows installer should work now! Sorry for the mess I made, I hope it's all good now!
Cheers man, enjoy your weekend.