I've released a number of bits of software through this blog that use Java Web Start to make it easier for you to download and install them. Unfortunately there appears to be a number of bugs which result in the installed shortcuts breaking and even causing the launch link on the web page to not work if you have previously run the application.
Well I upgraded PhotoGrid yesterday and everything broke. I'm assuming it may have broken for everyone else as well. It took me a while to figure out what went wrong and how to fix it so I thought I'd write it up here in case I've broken it for everyone else.
We can fix the problems using the Web Start cache viewer, which you can load by issuing the command
javaws -viewer(on Windows you can enter this command into the Run... dialog box accessed from the Start Menu), and which should look like...
Now select the application that won't start and click the red cross button to uninstall it. Even though it will now have been uninstalled Web Start still remembers some details which can be a problem. So in the drop down box at the top left switch to viewing Deleted Applications. A similar list will appear and go through the same steps (select and the red cross) to fully delete the application. You should now be able to re-install without any problems.
The problem only seems to arise when I have to edit the JNLP file that is used to launch the applications. Updating the actual code works flawlessly. On the plus side it is quite rare for me to need to edit the JNLP files and so I'm hopeful that once the applications are working again they should continue to work for the foreseeable future.
Apologies for any inconvenience and I hope it doesn't put you off using the bits of software I write.