1. Start thunderbird (fresh profile if you like; dismiss the new-account dialog)
2. Inspect the "Go" menu -- see what the command is for "Chat".
(I have to hit Alt+g to make the menu appear, and the command displayed
for "Chat" is Ctrl+Shift+C)
3. Press the Chat command (Ctrl+Shift+C for me on Linux)
ACTUAL RESULTS: Nothing happens.
EXPECTED RESULTS: Should open the chat window, as if you'd activated that menu item with the mouse.
I've tested this on release (15.01) and earlybird (17.0a2), and it affects both.
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0a2
Build ID: 20120918042014 (latest Earlybird)
OS: Ubuntu 12.10 beta
Perhaps there's a conflict on that keybinding?
In another bug report, someone said this is a conflict with Lightning's *C*alendar shortcut, but it seems you don't have lightning installed.
Correct -- I don't have lightning in my normal Thunderbird profile, and this also affects me in a fresh profile (no addons at all).
Yeah the key isn't connected to a command. Will fix in bug 786606.