I've been trying to fix this problem by searching through the many posts, but still haven't been able to resolve it: I've downloaded the most recent Java Developer Package and installed it on my MacBook Pro with Mac OS X Lion 10.7.4. I've also downloaded Eclipse (IDE 1.4.2, Platform 3.7.2). It appears to be well-known that you have to change the Installed JREs in Eclipse to point to the correct location before Eclipse will know where to find the appropriate files for a build. I've made this change (along with several permutations, I am currently using /Library/Java/JavaVirtualMachines/1.6.0_32-b05-420.jdk/Contents/Home/), but still no joy creating a HelloWorld program. An error occurs when I try to create a new project:
"Archive for required library: '/Library/Java/Extensions/ctx.jar' in project 'HelloWorld' cannot be read or is not a valid ZIP file"
Does anyone out there have any experience with this problem? Any help would be appreciated.