Assignment

I've divided all enroled students in course into 2 groups. When I enter the assingment module, it says I have 13 answers from my students. When I select any of the groups I see the words "No attempts have been made on this assignment", but I really know - they are in the group and they did send me an answer. Why I can't see them? Group mode is on, the groups separate well in grade report module. MOODLE v 1.9.5

Debug says:
Unknown column 'ra.userid' in 'IN/ALL/ANY subquery'

SELECT u.id FROM mdl_user u WHERE u.deleted = 0 AND (ra.userid IN (SELECT userid FROM mdl_groups_members gm WHERE gm.groupid = 20)) ORDER BY u.lastaccess
line 686 of lib/dmllib.php: call to debugging()
line 966 of lib/dmllib.php: call to get_recordset_sql()
line 4590 of lib/accesslib.php: call to get_records_sql()
line 1070 of mod/assignment/lib.php: call to get_users_by_capability()
line 519 of mod/assignment/lib.php: call to assignment_base->display_submissions()
line 43 of mod/assignment/submissions.php: call to assignment_base->submissions()

It's likely because of moving from 1.8.4 to 1.9.5. with moving all courses. How can I get things right??