Attaching T-adapter to SCT

[T_Tucks]

I bought my CPC 1100 with a baader focuser and diagonal already attached. Now that I have tried to put a T-adapter on, I see that I am missing something somewhere as it does not attach.

Should there be something between the telescope and the visual back (the visual back and if so is it easily replaced?

Thanks,

Tim

[Tinker1947]

This was my set-up, the bits you can't see are the 2" Moonlite extention that screws in to the FR then slides into the visual back, and the T-Extension that joins the camera to the Baader Click-lock