Here is a comprehensive guide to resolving this DLL issue and getting the game stable on modern Windows systems. Understanding the uplay_r1_loader64.dll Error
Add the entire Splinter Cell Blacklist folder to your "Exclusions" list. 4. Direct DLL Replacement (Last Resort) uplayr1dll splinter cell blacklist 2021
Ensure the file version matches your game version (standard vs. deluxe). Here is a comprehensive guide to resolving this