If you have Norton Antivirus as I do, you'll find that the latest Steam update with Swords of Fury is flagged as: Trojan.Gen.8!cloud, and then Norton completely removes the pinballarcade.exe file and you can't even launch the problem. A quick browse on the Steam forums and you will find lots of people having issues with this; the common denominator being Norton. I have sent an email to support@pinballarcade.com and hopefully they will resolve this issue quickly.