I just upgraded to 2011040108 on Moodle 2.5.2.
Since the upgrade I cannot open any report which contained a user search field. It just shows a blank page.
The Apache error log throws:
PHP Fatal error: require_once(): Failed opening required /home/moodle/moodle/blocks/configurable_reports/components/filters/fsearchuserfield/plugin.class.php' include_path='/home/moodle/moodle/lib/zend:/home/moodle/moodle/lib/pear:.:/usr/local/lib/php') in /home/moodle/moodle/blocks/configurable_reports/reports/sql/report.class.php on line 131, referer: https://si-vmerplmsdev.si.edu/moodle/blocks/configurable_reports/editcomp.php?id=163&comp=filters&courseid=1
The file is there, the permissions are correct (644).
Creating a new report with a user search field works fine.