Please follow these steps to resolve the "Failed to init security" issue under error code 0xE0191009.
- Download the bin64_2.zip file attached in this article.
- Move the zip to a new folder (for your ease, so you can easily locate the extracted files).
- Extract the zip.
- Move all of the extracted files to <installation directory>\Black Desert Online\bin64\xc\na\2 (make sure that you replace them when prompted).
- Start your game.
You can easily access your installation directory by right-clicking on your Black Desert Online Launcher and pressing "Open file location".