Hello and welcome to the semi ultimate guide to getting Risen 1 Updated to work.
There are quite a few issues, the teams are working on audio and some fov issues but so far they arent working on the main problem

Before starting, no matter what if you have an issue of any kind please follow this official link and make a detailed ticket.
They are ACTIVE and even have a beta out already
https://steamproxy-script.pipiskins.com/app/40300/discussions/0/3758851615160415964/

Now Onward!

Cant start the game at all ! !

Fault error xinput_ 3 / 4
*fix: same as all games from pb but this should be done for all pcs,
copy the xinput file needed paste it

If you cant start the game due to Xinput error, there are plenty of places that depending on which you need 3 or 4 etc
https://windll.com/dll/microsoft-corporation/xinput1-4

Physx Error
If you get a Physx error EVEN IF you don't run nvid or such.
https://www.nvidia.com/en-us/drivers/physx/physx-9-19-0218-driver/
Install this, restart pc.

If you can start it but a black screen appears

Black screen on start with g3 dll error behind

*Temp fix: Edit the config ini change res to 800x600 enter game,
set to 1920x1080 in game then after that go back to config set it to 1920x1080 vs 800x600
Config files are here and here.

%LOCALAPPDATA%\Risen\ConfigUser.xml

Steamapps<path-to-game>\data\ini\ConfigDefault.xml

Once you make it to main menu *whew wipes forehead

If you are in main menu, then click Start new game and it crashes after a loading screen
*temp fix

Find Risen.exe
Right click, select PROPERTIES
Go to Compatibility
On the bottom of this tab it will say High DPI scaling Override
Check the box, and make sure it says APPLICATION

This fix will work instead of manually going to Display settings and lowering Scaling to 100%
If the compat dpi doesn't work. Manually go to Display in windows and turn scaling to 100% not higher.
This will cause everything in windows to be smaller until you change it back.

Audio is SOOO low !

This one is easy, so I expect a fix really soon
Alt tab out of the game,
Right click windows audio icon and click Open volume mixer
Scroll right to the games exe, take note that its at 20%
Raise it to what you like *I prefer 70-75%
If you dont want to do that

Edit %LOCALAPPDATA%\Risen\ConfigUser.xml as follows:
<Audio
UseHardwareSounds="true"
>
<Volume
Master="765"
>
</Volume>
</Audio>
Fixed!
Save game issues, I have not run into any myself. I expect all should use new games to play. But I will look into this more as the beta patch branch keeps working.
Much love to this crew, idk whom you are but ty for even caring !

These should be very easy to mend on dev side! esp now you know you can replicate it and this is the issue.
All Crashes can now be fixed, minus ones in game that are bugs not related to scaling

I will post this in a new thread, if you feel the need merge or remove it,
But these infos are confirmed working by many users now