If post counts, thread counts or “last post” details look wrong in vBulletin, the underlying posts are usually fine. What has gone stale is the cached numbers, and those can be recalculated.
Why the numbers drift
Forum software does not count posts every time a page loads. That would be slow. Instead it stores running totals and updates them as people post.
If posts are added, deleted or moved outside the normal flow, those stored totals stop matching reality. Bulk imports and direct database edits are the usual causes.
What to do
vBulletin includes maintenance tools for exactly this, in the admin control panel under its maintenance or rebuild section. The exact menu wording varies between versions, so look for entries offering to rebuild or recount rather than following a fixed path.
The ones you typically want:
- Rebuild forum information — recalculates thread and post counts per forum, and fixes the last-post display
- Rebuild thread information — recalculates reply counts on individual threads
- Update counters — recalculates per-user post totals
Before you run it
- Back up the database. These tools write to a lot of rows.
- Expect it to take a while on a large forum. Some versions process in batches and need the page left open.
- Run it once and check before running the others. Often only one rebuild is needed.
If the numbers are still wrong afterwards, the problem is in the data rather than the counters — orphaned posts pointing at threads that no longer exist, for example. That needs looking at directly, not another rebuild.