I work as a Java developer/contractor at the moment, but unfortunately I don't have a Disklavier Mk IV to help with this. I suspect you will need to go back to an older version of Java 7 or Java 8 (Java 8 is the next major version, but updates are still released for Java 7 until April this year). Be warned that doing this will mean you could be running a more insecure version of Java and are potentially more at risk from malware.
There have been big changes in what files are trusted by Java when launching applets and WebStart applications - the JNLP file is used for Java WebStart - and this has affected a lot of corporate applications.
The major changes for WebStart came in with versions 1.7.0_45 and 1.7.0_51, but there have been a lot applied since then. Old versions of Java can be obtained safely from http://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html and http://www.oracle.com/technetwork/java/javase/downloads/java-archive-javase8-2177648.html.
I would suggest trying an older version of Java 7 and installing it alongside the current version, ensuring that the current version is used by your browser. You could then run a specific version of Java WebStart against the JNLP from the disklavier, eg by saving the VirtualPRC JNLP file somewhere and creating a shortcut for something like:
"c:\Program Files\Java\jre1.7.0_55\bin\javaws.exe c:\prcstart.jnlp". Worth a shot if nothing else. I9;d hope Yamaha are rewriting the Virtual PRC as a web application that doesn't require Java anyway, but perhaps that will be for Mark V owners only!
Good luck!
Regards,
James
On 11 February 2015 at 05:07, Bill Brandom bill.brandom03@... [disklavier] <disklavier@yahoogroups.com> wrote:
Hi Ken and Kevin,Yamaha is aware of this issue. We are awaiting information from our engineers to deal with this issue.I am using a MAC and had recently updated to Java version 8 update 31. Today, I reverted back to version 7 but I still could not use VirtualPRC.You can find instructions on how to revert your Java version here:If you do revert, can you let us know if you are able to access VirtualPRC?BillOn Tue, Feb 10, 2015 at 8:17 PM, ken@... [disklavier] <disklavier@yahoogroups.com> wrote:Kevin,
Yes, I've tried it both ways. Directly from the piano's VirtualPRC.html page. Plus using the prcstart.jnlp file I saved from the piano's VirtualPRC.html page. I'm on Java 8. I'm wishing I didn't have Java set to auto updateI may have to go back to version 7?-Ken