CB

When a username is formatted as digits-words it breaks the reversal of SEF URLs since it thinks the digits are a user id. Examples as follows.

20-tom
30-bob

Those attempt to navigate to profile with id of 20 or 30 instead of profiles with usernames of 20-tom and 30-bob.

https://www.joomlapolis.com/forum/255-developer-members-support/238727-username-format-this-profile-does-not-exist-or-is-no-longer-available?start=6#302799