When I check the attempts, let's say in the overwiew option, and I try to filter the attempts for surnames starting with certain letter (clicking in that letter), the following error appears:
ERROR: Mixed types of sql query parameters!!
and I can´t see the attempts anymore, until I leave Moodle and come back again.
Trying to use the filter option does not give errors, just does not filter anything
What can I do to fix this problem? Using Moodle 2.1.4+
Thanks in advance