I have a Java application in a .jar-file. I can start it by typing java -jar myapp.jar and the application starts, but if I double-click on the .jar-file, nothing happens. What can be wrong? How can I fix this? I use Windows Vista.

I have tried on another computer and it works fine there. It must be something with my Java configuration. I have another question with a similar problem on I can not start Eclipse anymore.


I had the same problem and finally solved it, download the jdk1.5 upgrade 3.
I had the exact same problem, even after reinstall, I was getting the main class not found error.
After installing jdk1.5 upgrade 3. Problem solved!

  • Is this the only alternative? 1.5_u3 is very old. – Jonas May 28 '10 at 8:42
  • If you're using Win XP (and maybe some earlier versions), try this: Start -> My Computer -> Tools -> Folder Options... -> File Types. There will be a list of extensions, so go to JAR. If it opens with javaw, click Change and select "Java(TM) 2 Platform Standard Edition binary", and all should be well. I had the same problem, but this fixed it. – admintech May 28 '10 at 8:49
  • 1
    I uninstallad all my jre and jdk, and reinstalled the latest version, that solved the problem. Thanks. – Jonas Jun 22 '10 at 15:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.