This plugin will add a tick box in the ACP under Moderator Options to force a user to change their username before they can continue to browse the forum and if they try to click away from the prompt forcing the name change they will again be automatically redirected back to the prompt.

This also includes TFLUsername plugin to keep a record of all name changes that have been forced. Also, for example if a user is in the Registered group and they don't have permission to change their name in the Group Settings this plugin will override that setting and still force the name change.