After the patch, many, like me, encountered the problem of passing the room with the cube. More precisely, after passing the “rotten room” the new door was not unlocked. I waited a long time for a solution to the issue, but without waiting, I downloaded the repack of the previous version and loaded my auto save before jumping into the hole.

For those who are too lazy to download the previous version of the game, I am attaching save files with the second part of the cube unlocked.

Place the contents in C:/Users/username/AppData/Local/SilentHill2/Saved/SaveGames/ folder with numbers.

Don't forget to change the settings to suit you.