by Pedro Ximenes.
Hi,
I'm using Moodle 2.9.2+ (Build: 20151008) and having same problem.
Unique Index mdl_assisubm_assusegroatt_uix from mdl_assign_submission table is generating errors.
Root cause is:
I had one assignment with multiple submissions from the same user. In the assign_submission table there is an attemptnumber field that the assignment upgrade script does not make use of. As a resut of the unique index - mdl_assisubm_assusegroatt_uix - the insert fails during one of the submissions and throws a database error. (https://tracker.moodle.org/browse/MDL-45806)How to solve it?
Many thanks!
Pedro Ximenes