I'm using the automatic upgrade package. I update the database, and when it comes to the step "Cleaning usernames", I have to change the username for one user. When I submit that, I get the following error:

Notice: Use of undefined constant UTF8_ASCII_RANGE - assumed 'UTF8_ASCII_RANGE' in /home/username/public_html/forum/install/data/new_normalizer.php on line 113

Fatal error: Undefined class name 'utf_normalizer' in /home/username/public_html/forum/install/data/new_normalizer.php on line 192

In install/data/new_normalizer.php, the class utf_normalizer is called. However, includes/utf/utf_normalizer.php (where utf_normalizer is defined) is not included in the upgrade script, thus resulting in new_normalizer.php calls an undefined class.