TYPO3 Core

Which exact TYPO3 version are you using?
What do you mean with "backend menu"? Do you mean the context menu when right-clicking an element in the page tree?

Version 6.2.2.
Same problem occurs on the demo site demo.typo3.org.
Backend menu that appears when you right click pages in the pagetree. In fact the error comes only when hovering pagetree.
Activate firebug and error appears.

Can't reproduce this. Tried it on one of my 6.2.3 installations.

You have firefox 30 and tried on typo3 demo site ?

Ok I see the error now too on my site, but the menu still works.

For me it doesn't work, I get the firefox menu instead.

It seems to be a bug in Firebug! If I disable it, things are working again.

This seams to be: https://code.google.com/p/fbug/issues/detail?id=7359

Thx Alex.

Note from there:

Note that the platform bug is fixed in Firefox 31

So you need following configs to workaround the problem

• Firebug 1.12.8 + Firefox 30
• Firebug 2.0 + Firefox 31+

And the bugzilla entry: https://bugzilla.mozilla.org/show_bug.cgi?id=996456

https://bugzilla.mozilla.org/show_bug.cgi?id=998908

Indeed it's linked to firebug. I have firebug 2.0.
What is strange is that a friend has firefox 30 and firebug 2.0 and he doesn't have the problem. With the same versions I do have the problem.