Sorry to say but it sounds like you may be playing a pirated version of the game. I purchased it on STEAM along with the walkthrough and have had no problems with missing content even though I prefer NOT to play such games on a client, particularly STEAM since they look over user shoulders, and in my own experience, like to mess with user save games. Among other things.
Not exactly making a guess... The typical issues you described in your previous post where very similar to issues players have had with many "Pirated" games downloaded from assorted sites. There of course are plenty of issues many games have with various platforms including Android, Mac, Linux, and PC. In any case. The game developer is the most likely source of any fix for the issues or for tips of how to address the issue in case it is a device compatibility issue due to another application installed interfering with the game. IE: Antivirus/Antimalware app, etc..
Just trying to offer tips to help.