Just installed the addon version 2.13.2-bcc on TBC 2.5.2
It worked great the first time I used it. CTRL+C brought up the addon popup with links.

After closing and relaunching the game, the hotkey no longer does anything. Using CTRL+C just brings up the character screen. CTRL+SHIFT+C similarly does not bring up any addon popup.
Typing /wql does bring up the options, so the addon must be loaded, just no longer responding to the hotkey.

I tried disabling all other addons except this one, but the issue persisted.

Since this was resolved, I'll close this out. I apologize for the extremely delayed reply, please feel free to open another issue if you encounter other bugs in the future!

Update: I saw this comment here and checked my key bindings. The binding had been cleared. I set it to CTRL+C and it's working again.