[krieck]

Your build is having trouble finding the WPILIB library files, which should be "wpilib" directory in your home directory.

The third line of your log (the one describing the classpath) is a little weird, like it knows which two JAR files to load, but doesn't know where they are. This line should usually be an explicit pair of file paths.

You could try diagnosing the build.xml and build.properties files (there are some in your project directory and others under the wpilib directory). Or, you could just try trashing your wpilib directory and then reloading the FRC plugins.