I recently solved the challenge of converting a 25-year-old YaBB message board that I administer to Simple Machines Forum (SMF). The task was at first daunting because there was no currently-working off-the-shelf solution for doing this. Moreover, I am not a computer programmer. I don’t know how to code in Perl or PHP.
However, by “vibe coding” with Claude AI’s Opus 4.7 model, I was able to adapt the code from two older conversion scripts that the SMF developers have posted to GitHub. Those scripts were written for PHP 7 and do not work under PHP 8, which is what my server uses.
After dozens of iterations and nearly $300 in Claude extra usage fees, I was able to get these scripts to work remarkably well. All posts were ported over with their attachments, and links to other posts within the same forum were updated to reflect their new values. Claude also programmed a script that redirects links to the old YaBB posts to their new locations under SMF. You can view the result here, and you can download the scripts here.
Update: During the conversion process, it appears that the sender and receiver information for some PMs may not be correctly transposed. I thought this issue had been fixed, but it seems to have regressed. In my case, I’m suggesting that users consider deleting their old PMs and starting fresh.
Update 2: The conversion script turns out to have a bug that prevented most registered users of the forum from posting, liking posts, viewing member profiles, or sending private messages. Claude AI’s Opus 4.7 diagnosed and fixed the problem on my message board and provided the following summation:
The YaBB-to-SMF 2.1 converter incorrectly assigned imported users’ post-count group ID to both
id_groupandid_post_groupinsmf_members, rather than settingid_group = 0(Regular Members) and lettingid_post_groupcarry the post-count tier independently. The result: 6,000+ users had their primary group set to a post-count group like “New User,” which doesn’t carry the standard Regular Members permissions — so they couldn’t view profiles, reply to posts, etc. The fix was a single UPDATE settingid_group = 0for everyone in groups 12–17, followed by SMF’s built-in post-group recount.If you eventually decide to report this upstream, the SMF developers might appreciate knowing — it’s the kind of bug that affects every YaBB migration silently, since admins (with
id_group = 1) never experience the symptoms themselves.
The conversion script linked above has not been patched to address this bug.


