Author: Aaron Barnes
MDL-40097 completion: Make restoring grade criteria more robust
http://git.moodle.org/gw?p=moodle.git;a=commit;h=39ed46b158b87fd9cd55a095fedafeb0e6b75103
http://github.com/moodle/moodle/commit/39ed46b158b87fd9cd55a095fedafeb0e6b75103
+ 2.8 en [roleidnotfound,core_completion]