Since this DLL belongs to the Ubisoft launcher (formerly Uplay), a corrupted launcher installation is often the culprit. Ubisoft Connect via Windows Control Panel.
If it was already deleted, restore it:
Contact Ubisoft Support: https://support.ubisoft.com far cry 4 uplay-r1-loader64.dll missing
If you’re on Windows 10/11:
: Open Windows Security , go to Protection History , and look for a recently blocked or quarantined file named uplay_r1_loader64.dll . Since this DLL belongs to the Ubisoft launcher