When trying to play a Blu-Ray disc on your Windows 10 computer using the VLC app you will sometimes get the error \u201cThis Blu-Ray Disc needs a library for AACS decoding". One of the main causes that triggers this error message is that the disk is protected by AACS and BD+ technology. Another possible reason is a missing KeyDB.cfg file. In this latest installment of our troubleshooting series we will tackle the Blu-Ray disc needs a library for AACS decoding issue. How To Fix This Blu-Ray Disc Needs A Library For AACS Decoding Issue To fix this problem you will just need to add some library files to VLC to enable it to decode AACS. Go to this link: https:\/\/vlc-bluray.whoknowsmy.name\u00a0Download the KeyDB.cfg fileGo to the AACS Dynamic library then click on the link of the VLC version that you are using.Copy the KeyDB.cfg you your clipboard then use file explorer to navigate.Press Windows key + R to open up a Run dialog box.\u00a0Type \u201c%APPDATA%\\\u201d and press Enter to open the hidden Appdata folder.Create a new folder (Right-click > New > Folder)\u00a0 and name it aacsOpen the newly created aacs folder and paste the KEYDB.cfg fileNavigate to your download folder and copy the libaacs.dll file to your clipboard.Use File Explorer to navigate to the install location of VLC and paste it there. The default location is C:\\Program Files\\VideoLAN\\VLC (64 bit) or C:\\Program Files (x86)\\VideoLAN\\VLC (32-bit).Open VLC and open the Blu-Ray disk that was previously failing with the \u201cThis Blu-Ray Disc needs a library for AACS decoding\u201d.\u00a0 At this point the Blu-Ray Disc Needs A Library For AACS Decoding Issue will already be resolved.