The uplay_r1_loader64.dll error in Assassin's Creed Unity typically occurs when your antivirus software mistakenly flags the file as a threat and quarantines it, or when the file becomes corrupted or missing. How to Fix the uplay_r1_loader64.dll Error
Most of the time, the file isn't actually "missing" but has been blocked by Windows Defender or third-party antivirus software. The uplay_r1_loader64
Right-click the Start button and select Terminal (Admin) or Command Prompt (Admin). Type sfc /scannow and press Enter. Restart your PC – Temporary glitches can cause DLL errors
ACU.exe → Run as administrator.Assassin's Creed Unity, developed by Ubisoft, is a popular action-adventure game released in 2014. However, some players have encountered a frustrating error, specifically the uplay_r1_loader64.dll error, which prevents them from enjoying the game. This report aims to provide an in-depth analysis of the issue and offer effective solutions to resolve the uplay_r1_loader64.dll error. Missing or corrupted uplay_r1_loader64
Then, he went back to the main game directory and looked for a file named uplay_r1_loader64.dll. It wasn't there (because he deleted it earlier), which was good.
Step 2: Repair UplayR1Loader64.dll File