Launcher crashes after patch! Game unusable.

[3./JG51_Heiden]

After Steam installed the patch, I get this error from Launcher.exe every time I try to play. It's a show-stopper!

Problem signature:
Problem Event Name: CLR20r3
Problem Signature 01: launcher.exe
Problem Signature 02: 1.0.0.0
Problem Signature 03: 4d6e3d08
Problem Signature 04: maddox
Problem Signature 05: 1.0.0.0
Problem Signature 06: 4d9f52b9
Problem Signature 07: 6023
Problem Signature 08: 79
Problem Signature 09: System.IO.FileNotFoundException
OS Version: 6.1.7601.2.1.0.256.1
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789