Tried to use this extractor to unpack archive.rpa files, doesn't work sadly.
^ This game. It's still in development phase and I just want to see how many CGs are there in the beta build. After I drag & dropped the rpa file (the filesize is more than 1gb), the program works as intended but then stopped working midway through (the window simply disappearing, leaving no extracted/decrypted files). I don't think my antivirus blocked it or interfere the process since there's no error pop out or something like that.
It works for me. It created the "date" folder, which contains the assets.
My theory why it didn't work for you:
1. You have very little RAM (turn off all other applications)
2. Your file path contains non-ASCII characters (russian characters in your username path perhaps). Move the game install files to C:\test\ for example and put the rpaExtract.exe in the same folder as archive.rpa, then follow the video instructions.
If it still doesn't work, you can try to run the tool in a command line or powershell .\rpaExtract.exe archive.rpa so you check whether there are any error messages when it crashes.