[BIG FIX] Common Issues on Modern PCs RESOLVED

Download the 4gb Patch from here https://ntcore.com/?page_id=371

This patch fixed the issue for me. It enables 32-bit execute files to have 4gb virtual ram instead of 2. Download it, apply it to your mafia2.exe at "steamapps\common\Mafia II\pc" and the issue should be resolved.

This issue is very common and is probably caused by your modern PhysX files. Go to your control panel, uninstall PhysX (All of them, both Legacy and Modern if you have em) The issue should be resolved. Also install the PhysX files from the game folders to make sure steam doesn't install the wrong files again.
How to? Go to "steamapps\common\Mafia II\3rd" and run the PhysX_9.10.0513_SystemSoftware.msi and let it install.

Run the game on windowed mode and it should be resolved. If the tab thing on the upper side is annoying, you can try out external borderless window programs, like the one I linked below.
https://github.com/Codeusa/Borderless-Gaming

During the car lock-pick mission, you'll likely encounter this error. It's caused by high framerates. Temporarily run your game at 60fps to bypass this issue. You can do it on your Radeon software with Radeon Chill. For Nvidia users, go to the Nvidia control panel > Manage 3D Settings > Global Settings > Max Frame Rate

Major Tom made this fix, but he no longer hosts the video nor the patch. You can download the shadow patch here:
https://drive.google.com/file/d/1yWW5w34vOmpgSmuQerb0Yk33eThNpHXl/view?usp=sharing
Simply go to Steam\steamapps\common\Mafia II\pc and paste the contents of the .zip file there.
The original post https://steamcommunity.com/sharedfiles/filedetails/?id=1702987531

Enjoy the game. Cheers! Give me feedback, maybe we can add more solutions to this list, or improve what is here.