In the past I could include firebug light as described here:
Html/Javascript debugging in JavaFX WebView
Unfortunately, the link
http://getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js
is currently broken.
I found the source code for firebug light at https://github.com/firebug/firebug-lite
However, I did not manage to include it from there or clone the repo and use it offline.
I also failed to include firebug-light.min.js from
https://cdnjs.cloudflare.com/ajax/libs/firebug-lite/1.4.0/firebug-lite.min.js
=> How can i include firebug light without access to http://getfirebug.com?
Having the same problem debugging an old embedded IE in an eclipse RCP app I searched my old disk archives and found the original sources.
A slighty adapted version of firebug-lite v1.2 can now be found here: https://lupatec.eu/getfirebug , visit the link for instructions or simply replace the original firebug url http://getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js by https://lupatec.eu/getfirebug/firebug-lite-compressed.js