Recently the Arduino IDE installation refused to start on my Mac with the following exception:
uncaught exception in main method: java.lang.UnsatisfiedLinkError: /Users/arun/arduino-0015/Arduio15.app/Contents/Resources/java/librxtxSerial.jnilib: no suitable image found. Did find: /Users/arun/arduino-0015/Arduino15.app/Contents/Resources/java/librxtxSerial.jnilib: no matching architecture in universal wrapper
Rather bizarre error and as far as I know, I hadn't mucked around with any settings. According to the Arduino forum it had something to with the Java version and suggested giving priority to Java 5 over Java 6. However this didn't work on my setup. Eventually I just downloaded the Java 6 compatible version of librxrxSerial.jnilib and replaced it in the package contents of the Arduino app. This fixed the problem.