MyBB Community Forums

Try to deactivate the login convert plugin and check if it works. If it doesn't then take a look at the link below where someone had a very similar problem.

Link: http://community.mybb.com/thread-78714.html

Also, make sure that after the merge, due to duplicate usernames, a prefix gets added to the username. For example:

Before the merge if there was a user with the username "Arbaz". The board that is being merged also has a user with the username "Arbaz", after the merge, the user from the board being merged will have a different username to prevent having two different accounts with the same username. First account will be Arbaz and second I believe will be Arbaz_import

It appears that some users are able to login with their credentials of the previous board, but not me the Founder/Admin.

Which password are you using to log in? New password or previous password? Does doing a password reset help?

Why would I need to do the password reset, I am logging in with the new password.

Wait, if you can log in with the new password and your members can log in too then what's the problem?