Disclaimer: This guide is intended for resolving issues with legitimate installations. If you are using unauthorized modifications, results may vary.
If you tell me the (e.g., v1.07), I can help you find a more accurate loader.
: Look for uplay_r1_loader.dll , uplay_r1.dll , and steam_api.dll from reliable sources like DLL-Files.com .
Delete any leftover launcher folders in C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher .
This typically happens when the game tries to call an achievement-related function that the loader file doesn't recognize—often due to a mismatch between Steam and Ubisoft Connect versions, or antivirus interference. Microsoft Learn Core Solutions to Fix the Entry Point Error Manual DLL Replacement
This is a —incorrect editing can corrupt the spool file and permanently desync your achievements. It should only be attempted if you fully understand the hex structure and have a backup of the original file. Disclaimer: This guide is intended for resolving issues
Click and look for recently blocked items related to the game folder. Select the file and choose Allow or Restore .
Are you using a , Ubisoft Connect , or physical version of the game?
Users often report encountering errors related to missing DLL files, loader issues with DLLs, or problems with Uplay not functioning correctly. Here are some common issues and their solutions:
If you are experiencing a "module not found" or "entry point not found" error when launching the game, reviewers and technical forums suggest these steps: :
Download and install the packages (specifically the 2010, 2012, and 2013 versions for x86 and x64). : Look for uplay_r1_loader
: The main executable file for the Single-Player ( SP ) mode of Assassin's Creed IV: Black Flag.
Open your Antivirus software (Windows Defender, Avast, etc.). Go to or Quarantine . Look for files labeled uplay_r1.dll or r1_loader.dll .
If you are playing a legitimate version of the game, the best first step is to verify the integrity of your files. This will automatically download any missing or corrupted .dll files.
Legacy games sometimes look for specific Uplay registry entries that become broken during software updates. Close your game and open the Windows Control Panel. Uninstall .
Right-click on and select Properties . Navigate to the Installed Files tab. Click Verify integrity of game files . Wait for Steam to redownload missing .dll files. On Ubisoft Connect Open the Ubisoft Connect desktop app. Go to the Games tab and select Black Flag . Click on Properties on the left menu. Under Local files , click Verify files . Step 2: Resolve Antivirus False Positives Microsoft Learn Core Solutions to Fix the Entry
Some users report that the "ac4bfsp.exe has stopped working" error is caused by a conflict with cloud saves.
If you have a specific question about Uplay, achievements, or DLLs, providing more context might yield a more precise answer.
However, AC4BF does not use all these mitigations robustly, which is why custom DLL loaders remain functional.
Technical note for researchers
