After CR 6525260, three messages are added into src/plugin/share/classes/sun/plugin/resources/Activator.java

applet.error.details.btn
applet.error.ignore.btn
applet.error.reload.btn

They are not used by any program. From the webrev http://oklahoma.east/deployment/www/webrevs/mfisher/6u4/redx/webrev/, tracing from onLeftMouseClick() in ErrorPanel.java to createThreeButtonsPanel in DialogTemplate.java. The result is that all the three buttons including both label text and mnemonic keys are from deployment.java not Activator.java. I think getting the message and memonic keys from Deployment.java is fine, but it's better to remove the unused messages in Activator.java.