On Windows 10 Build 1703, 64-bit Java web applets (*.jnlp) fail to launch from IE11 if the 64-bit Java JRE is installed (or both 64 and 32-bit). The workaround is to uninstall the 64-bit JRE and leave the 32-bit (or install it).

https://bugs.openjdk.java.net/browse/JDK-8185661