The error I get when trying to upload a CSV file with customised user fields is,
Debug info: Column 'data' cannot be null
INSERT INTO mdl_user_info_data (userid,fieldid,data) VALUES(?,?,?)
0 => 24,
1 => '4',
2 => NULL,
I know that a patch for this was posted under http://tracker.moodle.org/browse/MDL-16764 but this was for patching the core of Moodle 1.9 and, having followed the instructions still get the same problem.
I also saw that a more recent patch was posted https://github.com/tlock/moodle/commit/97f4e51d4f4e7e4ba697880ecdc33480a3d2e691 (from http://tracker.moodle.org/browse/MDL-31654), but there isn't actually a pre_process_profile_data function in the uploaduser.php script so I couldn't see what to do with that.
Does anyone have a fix for this?