"The movie database" now has movie specific boards.
If you are looking for somewhere to migrate to.
https://www.themoviedb.org/tv/873-columbo
Scroll down to 'Social' and click 'Discussions'.
Theres a "Go to Discussions" button.
I'll have to check thought out. Here's another option. Sorry that it's a cut-and-paste:
IMDb message boards are closing!!!
One possible solution, even if it's only a temporary one:
IMDB v2.0:
http://imdb2.freeforums.net
It's not to my taste (although I have joined) but it is a near duplicate of IMDb, albeit a more high tech version.
"It's a real burden being right so often." Captain Malcolm Reynolds, Firefly