I'm seeing these warnings...

Notice: Undefined property: stdClass::$type in /var/www/html/moodle33/backup/moodle2/restore_stepslib.php on line 2708

Notice: Undefined property: stdClass::$timesort in /var/www/html/moodle33/backup/moodle2/restore_stepslib.php on line 2712

and then...

Debug info: Column 'type' cannot be null
INSERT INTO mdl_event (name,description,format,courseid,groupid,userid,repeatid,modulename,type,eventtype,timestart,timeduration,timesort,visible,uuid,sequence,timemodified,priority,instance) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
[array (
0 => 'Anaesthesia Calculation (Quiz opens)',
1 => '<div class="no-overflow"><p>During your week on hospital anaesthesia you have 2 attempts to correctly complete a drug calculation using the quiz. It is probably a good idea to make your first attempt after completing the Breathing systems quiz on Monday morning.</p>
<p>If you have not passed after 2 attempts you must inform one of the senior rotation staff so they can go through this with you. Failure to complete the calculation after 4 attempts will result in a Cause for Concern being issued.</p>
<p> </p></div>',
2 => '1',
3 => 10387,
4 => '0',
5 => '89619',
6 => 0,
7 => 'quiz',
8 => NULL,
9 => 'open',
10 => 1493452800,
11 => '0',
12 => NULL,
13 => '1',
14 => '',
15 => '1',
16 => 1493477683,
17 => NULL,
18 => 8895,
)]
Error code: dmlwriteexception

I have tried a number of courses. It could, of course, be something in my local configuration but I'm not sure what. 

Suspicion must fall on MDL-58822 as this was related and only closed a couple of days ago