Applet Security Exception Problem

Troubleshooting General Help
1

I’ve finished my first game and it runs great. The only problem is that I want to make an applet for my site, but the game needs to read/write/delete its save data and get the user’s home directory. I created a keystore with keytool and selfcert’d it. I then pointed the keystore path to this file in my properties and entered my alias and password. Game compiles, but the applet crashes with this error:

This occurred while ‘Switching applet’
Invalid signature file digest for Manifest main attributes
java.lang.SecurityException: Invalid signature file digest for Manifest main attributes
at sun.security.util.SignatureFileVerifier.processImpl(Unknown Source)
at sun.security.util.SignatureFileVerifier.process(Unknown Source)
at java.util.jar.JarVerifier.processEntry(Unknown Source)
at java.util.jar.JarVerifier.update(Unknown Source)
at java.util.jar.JarFile.initializeVerifier(Unknown Source)
at java.util.jar.JarFile.getInputStream(Unknown Source)
at sun.misc.JarIndex.getJarIndex(Unknown Source)
at sun.misc.URLClassPath$JarLoader$1.run(Unknown Source)
at sun.misc.URLClassPath$JarLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.misc.URLClassPath$JarLoader.ensureOpen(Unknown Source)
at sun.misc.URLClassPath$JarLoader.(Unknown Source)
at sun.misc.URLClassPath$3.run(Unknown Source)
at sun.misc.URLClassPath$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.misc.URLClassPath.getLoader(Unknown Source)
at sun.misc.URLClassPath.getLoader(Unknown Source)
at sun.misc.URLClassPath.getResource(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.lwjgl.util.applet.AppletLoader.switchApplet(AppletLoader.java:1315)
at org.lwjgl.util.applet.AppletLoader$2.run(AppletLoader.java:909)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

I don’t really understand applet signing, but I read a tutorial and thought I did everything correctly. Any advice?

2

Use java.util.Properties instead of a text file, you cannot store stuff to the computer from an applet without a certificate.
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