by Ken Task.
Haven't seen the error before ... so this is investigation ...
line 37 (below after the comment) of backup/import.php has:
// The courseid we are importing to
$courseid = required_param('id', PARAM_INT);
In the moodle_backup.xml file of the .mbz un-compressed/archived backup
there is or should be a tag:
<original_course_id>195</original_course_id>
also a block of tags for the course which should look like (below is an example):
<course>
<courseid>195</courseid>
<title>PPACA</title>
<directory>course</directory>
</course>
either of those missing the courseid number?
Are you restoring to a new course or adding to an existing course?
'SoS', Ken