This is the link that arived to mail indox:

http://10.152.5.245/moodle/login/confirm.php?datawMnPz2CGLMiXEE1/aadfasdfasd

moodle sends the self registration email in html, encoded as quoted-printable.

The equal sign is lost whith quoted-printable encoding.

I have a 2 possible solutions:

.1 lib/moodlelib.php line 5872: $mail->Encoding = '8bit'; // before quoted-printable
.2 lib/moodlelib.php line 6097: $data->link = $CFG->wwwroot .'/login/confirm.php?data=3D'. $user->secret .'/'. $username; // added 3D