A temporary solution to fix the CS:GO Model Viewer
In this tutorial I'll be explaining a temporary fix for the CS:GO Modelviewer.
You'll require a single .dll file to make it work again that for some reason isn't included in the CS:GO Bin folder but is in the Source Film Maker Bin folder.
First you should go to the Source Film Maker Directory and copy: "$SteamDir/steamapps/common/SourceFilmmaker/game/bin/soundsystem.dll"
Than you'll have to go to the CS:GO Directory and paste it in the bin folder: "$SteamDir/steamapps/common/Counter-Strike Global Offensive/bin/"
Now you'll be able to launch the CS:GO Modelviewer again!
If you do not have Source Film Maker installed you can get the .dll file here: http://www.mediafire.com/?snva0e3afbh4lr5
Until Valve fixes this problem this is a good temporary fix to make it work again!