So I upgraded my os to Mavericks 10.9, and now when I try to launch Spiral Knights, it gives me a white screen and closes out. I tried to uninstall and reinstall it, but that didn't work. I downgraded my Java to 1.6, ant that did no good. If you have the same problem and have fixed it , PLEASE comment the solution!
Open up Terminal and enter "java -version" to confirm you are using Java version 1.6.
You need to make sure both JDK and JRE are version 1.6 -- JRE if you access Spiral Knights through the web browser and JDK if you run sk through Steam. Apple has some instructions on how to re-enable JRE 6 if you already upgraded to JRE 7 (since Oracle doesnt support JRE 6 anymore for OSX).