To re-register JNLP files with Java Web Start.app, use one of the following methods:
- In the Finder, open the /System/Library/CoreServices folder. Simply opening this folder will re-associate JNLP files with Java Web Start.app.
- Close the CoreServices Finder window.
- Open Terminal (located in /Applications/Utilities/).
- Type or paste the following command, then press Return:
- Close the Terminal window
/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister "/System/Library/CoreServices/Java Web Start.app"