Ifdoes not launch as expected, try these troubleshooting tactics.
Launch the MFJNLP file directly.
Locate MFJNLP.mfjnlp in the browser’s Download location (typically C:\Users\<username>\Downloads), unless saved elsewhere.
The expected behavior is the same as launching the Reflection for the Web session through the browser, in accordance to the selected deployment option (Hybrid or Launcher).
Launch RWebLauncher-settings.bat, which opens the IcedTea-Web Control Panel. From there you can troubleshoot specific settings.
Launch the .bat file from either location: