Default exception handler: Error reading from database Debug: ERROR:  could not determine data type of parameter $3

SELECT c.id AS conversionid, c.sourcefileid AS conversionsourcefileid, c.targetformat AS conversiontargetformat, c.status AS conversionstatus, c.statusmessage AS conversionstatusmessage, c.converter AS conversionconverter, c.destfileid AS conversiondestfileid, c.data AS conversiondata, c.timecreated AS conversiontimecreated, c.timemodified AS conversiontimemodified, c.usermodified AS conversionusermodified

                FROM mdl_file_conversion c

                INNER JOIN mdl_files conversionsourcefile ON conversionsourcefile.id = c.sourcefileid

                LEFT JOIN mdl_files conversiondestfile ON conversiondestfile.id = c.destfileid

                WHERE

                    conversionsourcefile.contenthash = $1

                AND c.targetformat = $2

                AND (

                    c.destfileid IS NULL OR conversiondestfile.id IS NOT NULL

                )

            UNION ALL

                SELECT

                    NULL AS conversionid,

                    orphanedsourcefile.id AS conversionsourcefileid,

                    $3 AS conversiontargetformat,

                    2 AS conversionstatus,

                    NULL AS conversionstatusmessage,

                    NULL AS conversionconverter,

                    orphaneddestfile.id AS conversiondestfileid,

                    NULL AS conversiondata,

                    0 AS conversiontimecreated,

                    0 AS conversiontimemodified,

                    0 AS conversionusermodified

                FROM mdl_files orphanedsourcefile

                INNER JOIN mdl_files orphaneddestfile ON (

                        orphaneddestfile.filename = orphanedsourcefile.contenthash

                    AND orphaneddestfile.component = 'core'

                    AND orphaneddestfile.filearea = 'documentconversion'

                    AND orphaneddestfile.filepath = $4

                )

                LEFT JOIN mdl_file_conversion orphanedconversion ON orphanedconversion.destfileid = orphaneddestfile.id

                WHERE

                    orphanedconversion.id IS NULL

                AND

                    orphanedsourcefile.id = $5

[array (

  0 => '8b57065a9d5ceccbef6de4eb4cb9f02c2b4cf3d0',

  1 => 'pdf',

  2 => 'pdf',

  3 => '/pdf/',

  4 => '15743766',

)]

Error code: dmlreadexception

* line 486 of /lib/dml/moodle_database.php: dml_read_exception thrown

* line 293 of /lib/dml/moodle_read_slave_trait.php: call to moodle_database->query_end()

* line 338 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->read_slave_query_end()

* line 986 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->query_end()

* line 179 of /files/classes/conversion.php: call to pgsql_native_moodle_database->get_records_sql()

* line 75 of /files/classes/converter.php: call to core_files\\conversion::get_conversions_for_file()

* line 215 of /mod/assign/feedback/editpdf/classes/document_services.php: call to core_files\\converter->start_conversion()

* line 319 of /mod/assign/feedback/editpdf/classes/document_services.php: call to assignfeedback_editpdf\\document_services::list_compatible_submission_files_for_attempt()

* line 95 of /mod/assign/feedback/editpdf/ajax.php: call to assignfeedback_editpdf\\document_services::get_combined_document_for_attempt()

, referer https://..../mod/assign/view.php?id=766564&action=grader&userid=23608