Debug info: ERROR: duplicate key value violates unique constraint "mdl_ques_catidn_uix"

DETAIL: Key (category, idnumber)=(10, ) already exists.

INSERT INTO mdl_question (defaultmark,questiontextformat,generalfeedback,generalfeedbackformat,penalty,length,name,questiontext,idnumber,qtype,category,stamp,createdby,timecreated,modifiedby,timemodified) VALUES($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16) RETURNING id

[array (

'defaultmark' => '1.0000000',

'questiontextformat' => '1',

'generalfeedback' => '',

'generalfeedbackformat' => '1',

'penalty' => 0.3333333,

'length' => 1,

'name' => 'Types of geography',

'questiontext' => '<p>Drag the words relating to each type of geography to the correct notepad.</p><p>This is an example of a <a href="https://docs.moodle.org/en/Drag_and_drop_marker_question_type">Drag and drop marker question type.</a>&nbsp;In this example, several markers can be dropped into the same region.</p>',

'idnumber' => '',

'qtype' => 'ddmarker',

'category' => '10',

'stamp' => 'boysenberry.local+181024024558+4FhEeD',

'createdby' => '2',

'timecreated' => 1540349158,

'modifiedby' => '2',

'timemodified' => 1540349158,

)]

Error code: dmlwriteexception

Stack trace:

line 489 of /lib/dml/moodle_database.php: dml_write_exception thrown

line 248 of /lib/dml/pgsql_native_moodle_database.php: call to moodle_database->query_end()

line 969 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->query_end()

line 1017 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->insert_record_raw()

line 422 of /question/format.php: call to pgsql_native_moodle_database->insert_record()

line 123 of /question/import.php: call to qformat_default->importprocess()