Unable to import from a specific course (Import usually works fine)

I am trying to Import some materials from one course to the other.
1. I click the Import link.
2. I Search for a specific course.
3. I click on it (from the results) list
4. I get the following error page:

Error writing to database
Debug info: MySQL server has gone away
INSERT INTO mdl_backup_controllers (backupid,operation,type,itemid,format,interactive,purpose,userid,status,execution,executiontime,checksum,controller,timecreated,timemodified) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
[array (
0 => 'd9091c552895f768b194e8093731a2c6',
1 => 'backup',
2 => 'course',
3 => '87',
4 => 'moodle2',
5 => 1,
6 => 20,
7 => '8',
8 => 500,
9 => 1,
10 => 0,
11 => '58f72a68405fe94f067166af10d761a1',
12 => 'TzoxNzoiYmFja3VwX2NvbnRyb2xsZXIiOjE2OntzOjExOiIAKgBiYWNrdXBpZCI7czozMjoiZDkwOTFjNTUyODk1Zjc2OGIxOTRlODA5MzczMWEyYzYiO3M6NzoiACoAdHl
.
.
====
A Very very looooong text was cut off because i could not submit the issue to the tracker.
( I think it is the cause of this issue, in the first place )
I will try to attached it in a different file
(nadav)
====
.
.

',
13 => 1323440008,
14 => 0,
)]
Stack trace:

line 397 of /lib/dml/moodle_database.php: dml_write_exception thrown
line 878 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
line 920 of /lib/dml/mysqli_native_moodle_database.php: call to mysqli_native_moodle_database->insert_record_raw()
line 69 of /backup/util/dbops/backup_controller_dbops.class.php: call to mysqli_native_moodle_database->insert_record()
line 312 of /backup/controller/backup_controller.class.php: call to backup_controller_dbops::save_controller()
line 137 of /backup/util/ui/base_ui.class.php: call to backup_controller->save_controller()
line 146 of /backup/import.php: call to base_ui->save_controller()

Error reading from database
Debug info: MySQL server has gone away
SELECT
bi.id,
bp.id AS blockpositionid,
bi.blockname,
bi.parentcontextid,
bi.showinsubcontexts,
bi.pagetypepattern,
bi.subpagepattern,
bi.defaultregion,
bi.defaultweight,
COALESCE(bp.visible, 1) AS visible,
COALESCE(bp.region, bi.defaultregion) AS region,
COALESCE(bp.weight, bi.defaultweight) AS weight,
bi.configdata
, ctx.id AS ctxid, ctx.path AS ctxpath, ctx.depth AS ctxdepth, ctx.contextlevel AS ctxlevel, ctx.instanceid AS ctxinstance

FROM mdl_block_instances bi
JOIN mdl_block b ON bi.blockname = b.name
LEFT JOIN mdl_block_positions bp ON bp.blockinstanceid = bi.id
AND bp.contextid = ?
AND bp.pagetype = ?
AND bp.subpage = ?
LEFT JOIN mdl_context ctx ON (ctx.instanceid = bi.id AND ctx.contextlevel = 80)

WHERE
(bi.parentcontextid = ? OR (bi.showinsubcontexts = 1 AND bi.parentcontextid IN (?,?)))
AND bi.pagetypepattern IN (?,?,?,?)
AND (bi.subpagepattern IS NULL OR bi.subpagepattern = ?)
AND (bp.visible = 1 OR bp.visible IS NULL)
AND b.visible = 1

ORDER BY
COALESCE(bp.region, bi.defaultregion),
COALESCE(bp.weight, bi.defaultweight),
bi.id
[array (
0 => '2743',
1 => 'backup-import',
2 => '',
3 => '2743',
4 => '53',
5 => '1',
6 => 'backup-import',
7 => 'backup-import-*',
8 => 'backup-*',
9 => '*',
10 => '',
)]
Stack trace:

line 394 of /lib/dml/moodle_database.php: dml_read_exception thrown
line 753 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
line 599 of /lib/blocklib.php: call to mysqli_native_moodle_database->get_recordset_sql()
line 1205 of /lib/pagelib.php: call to block_manager->load_blocks()
line 720 of /lib/pagelib.php: call to moodle_page->starting_output()
line 607 of /lib/outputrenderers.php: call to moodle_page->set_state()
line 2038 of /lib/outputrenderers.php: call to core_renderer->header()
line 328 of /lib/setuplib.php: call to core_renderer->fatal_error()
line ? of unknownfile: call to default_exception_handler()

Fatal error: Uncaught exception 'dml_read_exception' with message 'Error reading from database' in /var/www/html/moodle/lib/dml/moodle_database.php:394 Stack trace: #0 /var/www/html/moodle/lib/dml/mysqli_native_moodle_database.php(1218): moodle_database->query_end(false) #1 /var/www/html/moodle/lib/sessionlib.php(429): mysqli_native_moodle_database->release_session_lock('200783') #2 [internal function]: database_session->handler_close() #3 /var/www/html/moodle/lib/sessionlib.php(199): session_write_close() #4 /var/www/html/moodle/lib/dml/moodle_database.php(318): session_stub->write_close() #5 /var/www/html/moodle/lib/dml/mysqli_native_moodle_database.php(334): moodle_database->dispose() #6 /var/www/html/moodle/lib/dml/moodle_database.php(140): mysqli_native_moodle_database->dispose() #7 [internal function]: moodle_database->__destruct() #8

thrown in /var/www/html/moodle/lib/dml/moodle_database.php on line 394