jQuery not defined in Confluence 3.5.3

[T. J. T. J.]

Drop down menus, tree navigation and many of my plugins have all broke at once. The error console shows "jQuery not defined". I haven't made any changes to Confluence that I'm aware of and I'm running 3.5.3.

I'm wondering if the header isn't rendering, and that's why jQuery isn't being defined.

[T. J. T. J.]

I restarted the server and the problem went away.

[David at David Simpson Apps]

That's weird -- go into Confluence Admin | Plugins and check to see whether any System Plugins have become disabled.

[T. J. T. J.]

Sadly the plugin admin area isn't working either with jquery broken.

[T. J. T. J.]

I ended up just restarting the server and now everything works. I'm still not sure why/how it broke.