I believe this is caused by the <shortcut/> element not being in the correct location in the JNLP file. It should be in the <information/> element. I ran into this using the ant tasks to generate a JNLP file, I'm not sure how Netbeans is creating the file. I reported this bug here: https://javafx-jira.kenai.com/browse/RT-27106. There are a couple of solutions mentioned in that Jira.