With the current Java Version 8 Update 102 WebStart applications will freeze because of an internal JVM deadlock. Oracle is aware of this issue, the bug is (partly) visible to public at http://bugs.java.com/view_bug.do?bug_id=8161700 There is no workaround for this issue so we strongly recomment not to update to this version. Please stick to version 8u101, which is the latest security update provided by Oracle.
If the application locks up, the thread dump will show the following pattern:
java.lang.Thread.State: BLOCKED (on object monitor)
at com.sun.deploy.security.DeployURLClassPath.getLoader(Unknown Source)
- waiting to lock <0x________> (a com.sun.jnlp.JNLPClassLoader)
Will will post any updates here, if you want to contact our technical support team concernig this issue please refer to this post or our internal bug id: #190088.