See https://www.phpbb.com/community/viewtopic.php?f=466&t=2336171

There is a bug in the user lookup function. You can't find unactivated users using the email address.

I've noticed that when I go to look an inactive user to activate him, using the user's email address, I cannot find the user via the admin panel's Manage Users function.

The Manage Users function should be able to load an inactive user. Inactive Users are still Users, just with a flag set a different way.

There is no reason for the user lookup to be excluding inactive users. It is more correct for it to find all users, active or inactive.

To fix this bug, simply change the lookup so that the inactive users are not excluded. Thanks.