I’ve been going over this for days trying to import forum using the Example importer. Everything works but after importing about 300,000 records, all of the authors are incorrect after the import. I did a fresh install of WP and tried again but got the same results. I ran the bbpress tools and this made no difference.
A lot of the users show as “Anonymous” but the rest are just pointing to the wrong user id. So the Topics/Replies just show as from the wrong user. I tried working around this by going into the source data and giving all of the user ids there a very high numerical value but even after doing this it made no difference. WordPress still assigns seemingly random userids to all of the imported users.

[@johnjamesjacoby Keymaster 3 years, 10 months ago]

Hi there. Sorry that you’re having trouble. What forum software are you importing from?

[@xprojectsx Participant 3 years, 10 months ago]

it’s a very old unsupported forum called bspeak. so I am using the Example importer. the imported fields are standard enough though. userid, forumid, threadid, msgid

I’ve been trying to figure out the logic in the importer but I cannot find the logic for converting the old userid to the new wp id. I suspect it is related to the join area in the example importer and the user logic in the converter.php but I simply don’t see any function like that.

I also tried an old suggestion from this forum to create a dummy user with a wp ID that is higher than the highest import userid. But this did not help.