Sometimes users get a "cannot create thumbnail" error when trying to use a PowerPoint file in MediaShout.  There are several different possibilities why this can happen.  Here are some things to check for troubleshooting this issue:

1. Go to My Shout > V4 > Thumbnails and delete all the thumbnails in this folder.  (My Shout > Thumbnails in v3)
2. Uninstall and reinstall PowerPoint.
3. If you are creating a PowerPoint file in a different version of PowerPoint on another computer, make sure that you save the file as the same version that you have on the presentation system.
4. Go to Tools > Settings > Applications > Slideshow Player.  MediaShout will display the PowerPoint application that it is attempting to use for slideshow cue playback.
5. If you have the PowerPoint Viewer and the PowerPoint FULL Version on the computer, uninstall the PowerPoint Viewer.
6. If you do not have PowerPoint on your system, you will need to install either the PowerPoint Viewer 97, or the FULL version of PowerPoint 2003,  2007, or 2010.  MediaShout only supports these versions.
7. Test other PowerPoint files and make sure the original file is not corrupted.