My MAC running OS X Lion ran an update yesterday which updated the installed version of Java to 1.7 (Java 7). Java 7 is a 64-bit only virtual machine, and it seems as though the KindlePreviewer app supplied by Amazon requires 32-bit. When double-clicking the app, it fails to launch, printing this to the console:
com.amazon.KindlePreviewer: Error: This Java instance does not support a 32-bit JVM
To get the KindlePreviewer working again, you need to make sure it points to Java 1.6. In your favourite text editor open:
and add JAVA_HOME pointing to your JDK 1.6 installation right after #!/bin/sh, e.g.
Save the file. Double-clicking the app should now work.
Update – 26th March 2013: Another update to the Kindle Previewer has been pushed out and it has replaced the .app file, removing the Launcher edits which I had put in place. Having changed the file again, adding the export line above, I am once again able to launch the Kindle Previewer app. It really surprises me that Amazon have not sorted this issue out almost six months after it was first found (and reported to them).
Update – 15th February 2014: Once again, following an application auto-update, the settings were wiped and I have had to manually correct the issue.