Couldn't find a scn discussion in "discussion archive"

I find the scn discussion "E-mail from CDT signature icons are not displayed" by keyword "

"reply template" font

" using X-search. And then after clicking the title, I got the error "Sorry! The requested content could not be found.

This may be because the content has not been migrated.

". I tried to searching it in the discussion archive, but didn't find it. Could anyone help find the reason? Is that because the discussion has not been migrated?