Please help me.
In my case, I can avoid the crash issue after removing the font files I had installed into my account.
And you need to install Java into El Capitan at first if not.
I hope I could help you.
I installed El Capitan 10.11.4 a week ago and no matter what I tried Fireworks CS6 crashed on launch. I have been using Fireworks for many years now, since v2, and have a ton of artwork created in it for websites, logos, maps, GIF animations and game apps.
I am so relieved to find your solution.
Uninstall CS6 with the Adobe Un-installer, including the preference files, quit any browsers, get the Java version you suggest using the link above, install, reboot, install FW CS6 after downloading a new copy from your account at Adobe. (Back-up both installers on an external drive... for future!)
Enjoy access to your old FW files once more.