My first upgrade was with plugins enabled, which resulted in an error.
Today, I did a whole new copy and upgrade with all plugins disabled.....same error.
Code:
Warning: require_once([path]/includes/functions_wysiwyg.php) [function.require-once]: failed to open stream: No such file or directory in [path]\itrader_feedback.php on line 187
Fatal error: require_once() [function.require]: Failed opening required 'C:\htdocs\forum/includes/functions_wysiwyg.php' (include_path='.;C:\php\PEAR') in C:\htdocs\forum\itrader_feedback.php on line 187