I've seen this on other posts, but I can't find a solution that works. Here's what I tried so far:

Running both Cube.exe and the cubelauncher.exe as administrator

Set compatability mode for both cube.exe and the launcher. Tried Windows XP (Service Pack 3), Windows XP (Service Pack 2), Windows 7, and Windows 8. Windows 8 doesn't throw the error if it's not run as administrator, but CubeWorld still doesn't run. Also, it does throw the error if it is run as administrator. Weird.

Unplugged my headphones

Uninstalled/reinstalled the game

Restarted Windows Audio in run > services.msc

Disabled speakers

Played around in advanced speaker properties

Just ran the new Windows update, so all of my drivers have been updated, as well as DirectX. Still the same error.

If anyone has any ideas, I'm all ears.

EDIT: I found the fix. If you are having this error, follow the following link:

http://www.microsoft.com/en-us/download/details.aspx?id=8109

Download the installer, and run the DXSETUP.exe that is extracted into the install folder. Works perfectly now.