There isn't a cpnav file..

I know that there isn't a cpnav xml, so the navigation must be built somewhere in a plug in. But I could not find this either ...

ha ha ha ha h...

Ya think?
I am most probably the worst

well it's name is "activity modification" and it's location is: "admin_index_navigation" you can just disable it because it should work..

Ok this should work a treat, disable the above plugin and then upload the attached xml file to /includes/xml and then it should work :)

...not quite! I followed your instructions and uploaded the new file. After that I logged out off the acp, cleared all cookies and logged back in again. But the new CP_nav doesn't show up. And because of disabling the plugin, the old one doesn't either (as expected)

hmm, i tested it on mine so i can't see why it shouldn't work..

I will investigate the failed start of board problem, and the CP nav issue. Is the CP nav issue only with 3.6?

seems tobe working fine so far on 3.6.0

Don't know. I didn't install that on my 3.5.4 Board ...