Deleted 23 days ago
I just tried in a quite vanilla -but updated - Win10 VM and it worked.
1. Re-download the game, the rpa file might be corrupted
2. Triple-check you drag/give-as-parameter the archive.rpa file and not some other file
3. Ensure the game is off (the file is not blocked?) while you extract
4. Restart windows (yes I know it's 2021 but still), allow all pending updates to finish. Perhaps even run updates to fix things broken by previous updates (Just a month ago I had to help fix a computer that just decided onboard audio doesn't work and windows update "fixed" it)
5. Use the macOS/Linux method (see description)
6. Oh boy. I can only think of tiny RAM, defective RAM, defective HDD/SSD, defective other hardware or simply an environment that is somehow weirding the script out, which obviously is using zlib. Perhaps you are a dev/packager and somehow added a "bad" (read this scrip can't handle it) version of zlib to path?
Dragonunpacker also works when used on an .rpa file, hopefully for you as well: