I was pulling out my hair wondering why my Pinball FX3 - Alien Isolation table was not displaying the backglass video, table video or wheel after upgrading to PinballX V2.68. I uninstalled/reinstalled and then restored a backup of my media and my database files and it still wouldn't display. I knew the media files themselves were not the issue.
I finally tracked it down to the following:
There was a colon ":" in the description of the game in the Pinball FX3.xml. When I removed the ":" all the media started working again. The colon has always been a part of the description in my setup so this appears to be due to the latest update.