Unable to launch Designer


I am a newbie here.
I have installed Ignition 7.7. It works fine until I want to launch the designer . have this environment:

  1. Java 8, last version
  2. Firefox browser
  3. Ubuntu 14.04

Please could you help?
Thank you.

Here below the error :

at java.util.StringTokenizer.(StringTokenizer.java:199)
at java.util.StringTokenizer.(StringTokenizer.java:221)
at com.sun.deploy.util.SearchPath.findOne(Unknown Source)
at com.sun.deploy.config.UnixPlatform.getBrowserPath(Unknown Source)
at com.sun.deploy.config.ClientConfig.versionUpdateCheck(Unknown Source)
at com.sun.deploy.config.ClientConfig.init(Unknown Source)
at com.sun.deploy.config.WebStartConfig.init(Unknown Source)
at com.sun.deploy.config.ClientConfig.(Unknown Source)
at com.sun.deploy.config.WebStartConfig.(Unknown Source)
at com.sun.javaws.Main.main(Unknown Source)

In fact, I change the browser to Chrome and it works fine now.

This error is only occurring when you are selecting the link for the designer in Firefox ? What is the current version of Firefox that you are using ?