If you have migrated to a new platform, generate a map from old archive URLs to new ones. Use a simple script to loop through all thread IDs and output:
/archive/index.php/t-123.html → /new-forum/threads/123/
Upload this as a redirect map in your server config or use a plugin like Redirection (WordPress) or Route Changer (XenForo). Topic Links 2.2 Archive Fix
Because we couldn't rewrite 12,000 HTML files by hand (without breaking existing deep links from Google), we deployed a lightweight Cloudflare Worker / Apache .htaccess rewrite rule.
The logic:
We didn't have the source code for the original 2.2 parser. But we had 12,000 archived HTML files and a SQL dump of the original topic map. Here is the fix we built.
If you no longer run PHP on your server but have a static HTML export of the archive, or if you prefer not to modify core files, use URL rewriting. If you have migrated to a new platform,
Create or edit .htaccess in your archive/ directory:
RewriteEngine On
RewriteBase /forum/archive/
For large-scale archives, the PHP or .htaccess fix alone may not be sufficient. Links may be stored incorrectly inside posts or in search engine indexes. The logic: We didn't have the source code