Lua errors?

How am I suppose to report these?

I have had a couple already, and I get this Lua error window with a lot of code in it. The last quest that seemed to trigger it, I just wrote "Lua error" in the field where you report bugged quest, is that enough, or am I suppose to copy the error code and send it? (assuming they can track it in their system, which is why I just wrote Lua error the the bug report field for the quest.

I am not using any addons, so can't be that. I got macros though, but those are mostly for healing while in restoration spec, which I haven't been doing so far.