Links from the old forum result in a “page not found” error.
I’m not sure, but I think the old forum is down from now on, and this forum has thread copies therefore. Links to pictures, attachments and similar uploaded there might therefore also be dead, unless they’re copied also.
Perhaps this thread should be moved to the Site Feedback forum?
Yes, links on Google pointing the old forum won’t work. Not sure whether they’ll be able to forward them. In the mean time, you can search for the same topic on these forums and should get you same or similar results.
If by any reason you’re like me and just like Google everything, then you can still view the old forums link using the cached page from Google. Just click on the little triangle at the right side of the link and then click on Cached.
You are right about the “Site Feedback forum”. Who is going to move it? The admins or me, if so, how? Thank you…
Google search was another aspect. Your suggestion works fine for that. Thank you. But I was trying to point out the links (like in the attached picture) inside the Solar2D forum, which I think Solar2D admins could solve.
This one is an unfortunate case. The issue is that this article no longer exists. Being that it’s from 2013 maybe it was removed as there are newer/better ones?
Whatever the reason may be, you can see on this link that 11/26 in fact doesn’t exist, only 25 and 27:
I know it doesn’t help you, but just wanted to point out that links to the blog themselves is not the issue… at least not yet. 
That’s a separate issue.
The Corona Labs website still exists, unlike the old forums. If an individual blog post is missing, then that’s because it was deleted by whoever posted it or by someone else with sufficient access.
The issue with the forums could be fixed by using 310 redirect to the new forums (see https://stackoverflow.com/questions/8450573/how-to-301-redirect-an-entire-domain-while-preserving-the-path). However, I haven’t performed such an operation in a long while and I don’t remember if it can be applied only to the forums subdomain or if we need to wait for the Corona Labs website to be closed first.
As long as the URL structure the sane, this should work.
However it would require access to the forums.corornalabs.com domain/FTP to add the htaccess rewrite rules.