Windows, I assume? There's a few existence checks on both versions so I can't tell what it is without the exact error message. None of which is a check for renpy . If you want troubleshooting of the cheat injector, please post the error message and what OS (and version) you're on so we're not getting off topic here.
But, in general, here are the requirements/checks for each:
Windows:
- powershell (some windows versions will turn it off/make inaccessible)
- python.exe (not on the system. Renpy games come shipped with a copy of python. Imagine my surprise when some still ship with python2.7 -_-)
- rpatool is decoded from base64. The .bat has rpatool.py in base64 in the script. powershell is used to decode that back to a .py file that python.exe can use to extract the archive. Although the script should generate this, if there's a read-only setting on the directory or something similar that prevents the script from writing out to that directory, it won't be able to write out the decoded file and the check on it will fail.
- Same as 3 but cheat.py is what I wrote to modify the game.
- Checks to see if it's in the right directory
- Checks for backup files (linux version backs up the files it modifies)
- Checks to see if Perl exists
- Checks if some example files exist.
- if not, checks if rpatool exists
- if not, download rpatool via wget
- if not, checks if rpatool exists
