The quickest fix for a missing DLL error is to reinstall the game. To do this, please follow these steps:
1) Right-click on the Beat Saber shortcut icon in your Start Menu and select Compact from the menu options.
2) This will delete everything except for one file, which you should move over to an external drive or piece of storage that does not contain any other games. It is recommended that you save it somewhere else first before continuing because if anything goes wrong during installation it could overwrite important files with garbage data or corrupt your hard drive completely.
3) Now enter C:Program FilesBeat SaberInstaller_x64 into your address bar (you may need to scroll down). You will be asked whether or not you want to open a folder; click yes and then wait until all folders are opened up so they can be seen properly by Windows Explorer/File Explorer due to how showing hidden folders works on Microsoft operating systems (Windows 8+ only).
4) Inside Installer_x64 there should now exist an executable named install. Double-click on this programs icon and wait for it load up inside its window ǀif nothing happens when doubleclicking then hold shift while clicking once again but dont worry, just keep trying! ǀand at last hit Enter after waiting patiently. Wait awhile as this process may take some time depending upon how much data needs updating within Windows Update itself - usually around 20 minutes give or take 10 seconds here either way though! Just sit back relax while Beat Saber loads onto your computer without any errors whatsoever!