in windows 11, Battleeye is causing driver signature issues with the core isolation ( kernel-mode hardware enforced stack protection) because it comes with older batteeye version.

step 0- remove old battleeye from system, ( by checking services from there you can see the location, most of the time its in C:\Program Files (x86)\Common Files\Battleeye)
delete the folder

step 1 - download insurgency,( only download , do not run)

step 2 - download game called 'Unturned' (1.2gb)

step 3 - run the game. it will automatically install the latest version of battleeye.

step 4 - go to the game folder of insurgency and rename the battleeye folder of insurgency to anything (like add 123 or sfsdsfs)

step 5 - go to the game folder of unturned and copy the battle eye folder of unturned.

step 6 - go back to insurgency folder, and paste the battle eye from the unturned.

step 7- now go back to the renamed battle eye folder of insurgency , inside there will be a file named BElauncer.ini, copy only that file

Step 8 - go to the copied folder of battle eye and delete the file BElauncer.ini and paste the file from the renamed battle eye folder of insurgency.

Step 9 - now run the game insurgency

step 10- enjoy