We have a server that builds our client and we wondered why we couldn’t hear sounds (only a few music files worked).
Now we saw that we get this error:
Any hints? 
We have the same issue about mp3 files in the auto-build process on the remote Windows box.
Connecting with the mstsc.exe program is our only way to login on that remote Windows box, and the problem occurs only after we disconnect our Remote Desktop Services session while keep the Unity building process running.
After simply searching with Google, I found the log message “This command failed because System::init or System::setDriver was not called” is printed by the FMOD lib. It could be be a bug of the Unity editor incorrectly using FMOD.
I just read in other forum post that you can fix this problem by fixing sound driver configuration on Windows machine.
If you bump into this problem, it might worth checking if that machine can read&play sound outside Unity.
(the post was in Facebook and difficult to include link here, so just quick summary)