Alguém sabe como resolver isso? Eu tentei muitas coisas, mas nenhuma delas funcionou.

E quando clico em mais detalhes, recebo isso:

at sun.security.provider.JavaKeyStore.engineLoad(Unknown Source)
atsun.security.provider.JavaKeyStore$JKS.engineLoad(Unknown Source)
at java.security.KeyStore.load(Unknown Source)
at com.sun.deploy.security.RootCertStore$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.deploy.security.RootCertStore.loadCertStore(Unknown Source)
at com.sun.deploy.security.RootCertStore.load(Unknown Source)
at com.sun.deploy.security.RootCertStore.load(Unknown Source)
at com.sun.deploy.security.ImmutableCertStore.load(Unknown Source)
at com.sun.deploy.security.TrustDecider.isAllPermissionGranted(Unknown Source)
at com.sun.deploy.security.TrustDecider.isAllPermissionGranted(Unknown Source)
at sun.plugin.security.PluginClassLoader.getPermissions(Unknown Source)
at java.security.SecureClassLoader.getProtectionDomain(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(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 sun.applet.AppletClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.applet.AppletClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.applet.AppletClassLoader.loadCode(Unknown Source)
at sun.applet.AppletPanel.createApplet(Unknown Source)
at sun.plugin.AppletViewer.createApplet(Unknown Source)
at sun.applet.AppletPanel.runLoader(Unknown Source)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)