BuddyPress.org

Okay, I’ve reread this thread for the second time. You state that:

The problem must be with the data; since a fresh install works perfectly and after the data gets imported, I get the nasty 404 bug.

Andy’s answer is:

This is normal with WPMU, you are not going to be able to transfer over blog tables as there are all sorts of URL settings in the DB.

I have a few questions based on this interchange:

1. Which version of MySQL are you (is your host) running?
2. Have you tried repairing the DB tables before reimport?
3. Are you moving your data between different domains?

Since WPMU 2.7.1 + BuddyPress 1.0 + standard themes work fine with a new, empty MySQL DB, the issue is, as you state, with the data. Either you have data corruption, indices that need reindexing, or hardcoded links within the tables that are causing the 404s.

If the domain mapping is not identical to the hardcoded links in your WPMU tables, you will have issues.

So, here’s what I’d suggest:

1. Backup your data again
2. Then, repair/reindex
3. Then, if your domain mapping is not identical, follow these instructions keeping in mind that these articles are for WP and not WPMU. You’ll have to adjust accordingly:

   • https://codex.wordpress.org/Changing_The_Site_URL
   • https://codex.wordpress.org/Moving_WordPress