Sometimes Windows Defender or 3rd party Antivirus flags the Ubisoft loader as a "False Positive" and quarantines the DLL file, making it inaccessible to the game.
If you are trying to launch Assassin’s Creed Unity on your Windows PC and are greeted by a pop-up error mentioning uplay_r1_loader64.dll , you are not alone. This is one of the most persistent and frustrating launch issues for this particular title. Sometimes Windows Defender or 3rd party Antivirus flags
If one method fails, do not get frustrated. Move to the next. In 99% of cases, combined with Method 5 (Verify Files) will solve the issue permanently. If one method fails, do not get frustrated
: Check your antivirus (like Windows Defender or Malwarebytes) protection history. If the file is flagged as a threat, restore it and add the game folder to your exclusions list so it isn't deleted again. : Check your antivirus (like Windows Defender or
Missing system libraries can cause the DLL error even if the file is present.