diff --git a/admin/settings/courses.php b/admin/settings/courses.php
index f9afd0a382c..9e379a4c83c 100644
--- a/admin/settings/courses.php
+++ b/admin/settings/courses.php
@@ -221,7 +221,7 @@ if ($hassiteconfig or has_any_capability($capabilities, $systemcontext)) {
         2 => new lang_string('storagecourseandexternal', 'backup')
     );
     $temp->add(new admin_setting_configselect('backup/backup_auto_storage', new lang_string('automatedstorage', 'backup'), new lang_string('automatedstoragehelp', 'backup'), 0, $storageoptions));
-    $temp->add(new admin_setting_configdirectory('backup/backup_auto_destination', new lang_string('saveto'), new lang_string('backupsavetohelp'), ''));
+    $temp->add(new admin_setting_special_backup_auto_destination());
     $keepoptoins = array(
         0 => new lang_string('all'), 1 => '1',
         2 => '2',
diff --git a/backup/util/helper/backup_cron_helper.class.php b/backup/util/helper/backup_cron_helper.class.php
index 671a8b51501..21bebe89a71 100644
--- a/backup/util/helper/backup_cron_helper.class.php
+++ b/backup/util/helper/backup_cron_helper.class.php
@@ -397,16 +397,11 @@ abstract class backup_cron_automated_helper {
             $outcome = self::outcome_from_results($results);
             $file = $results['backup_destination']; // May be empty if file already moved to target location.
 
-            if (empty($dir) && $storage !== 0) {
-                // This is intentionally left as a warning instead of an error because of the current behaviour of backup settings.
-                // See MDL-48266 for details.
-                $bc->log('No directory specified for automated backups',
-                        backup::LOG_WARNING);
-                $outcome = self::BACKUP_STATUS_WARNING;
-            } else if ($storage !== 0 && (!file_exists($dir) || !is_dir($dir) || !is_writable($dir))) {
-                // If we need to copy the backup file to an external dir and it is not writable, change status to error.
-                $bc->log('Specified backup directory is not writable - ',
-                        backup::LOG_ERROR, $dir);
+            // If we need to copy the backup file to an external dir and it is not writable, change status to error.
+            // This is a feature to prevent moodledata to be filled up and break a site when the admin misconfigured
+            // the automated backups storage type and destination directory.
+            if ($storage !== 0 && (empty($dir) || !file_exists($dir) || !is_dir($dir) || !is_writable($dir))) {
+                $bc->log('Specified backup directory is not writable - ', backup::LOG_ERROR, $dir);
                 $dir = null;
                 $outcome = self::BACKUP_STATUS_ERROR;
             }
diff --git a/lang/en/moodle.php b/lang/en/moodle.php
index 1701cbb5317..529a654e970 100644
--- a/lang/en/moodle.php
+++ b/lang/en/moodle.php
@@ -177,6 +177,7 @@ $string['backupdatenew'] = '  {$a->TAG} is now {$a->weekday}, {$a->mday} {$
 $string['backupdateold'] = '{$a->TAG} was {$a->weekday}, {$a->mday} {$a->month} {$a->year}';
 $string['backupdaterecordtype'] = '<br />{$a->recordtype} - {$a->recordname}<br />';
 $string['backupdetails'] = 'Backup details';
+$string['backuperrorinvaliddestination'] = 'The backup destination folder does not exist or is not writable.';
 $string['backupexecuteathelp'] = 'Choose what time automated backups should run at.';
 $string['backupfailed'] = 'Some of your courses weren\'t saved!!';
 $string['backupfilename'] = 'backup';
@@ -194,7 +195,7 @@ $string['backupnonisowarning'] = 'Warning: this backup is from a non-Unicode ver
 $string['backupnotyetrun'] = 'Automated backup pending';
 $string['backuporiginalname'] = 'Backup name';
 $string['backuproleassignments'] = 'Backup role assignments for these roles';
-$string['backupsavetohelp'] = 'Full path to the directory where you want to save the backup files<br />(leave blank to save in its course default dir)';
+$string['backupsavetohelp'] = 'Full path to the directory where you want to save the backup files';
 $string['backupsitefileshelp'] = 'If enabled then site files used in courses will be included in automated backups';
 $string['backuptakealook'] = 'Please take a look at your backup logs in:
   {$a}';
diff --git a/lib/adminlib.php b/lib/adminlib.php
index 19ca8849ead..a921eaa0143 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -4390,6 +4390,44 @@ class admin_setting_special_backupdays extends admin_setting_configmulticheckbox
     }
 }
 
+/**
+ * Special setting for backup auto destination.
+ *
+ * @package    core
+ * @subpackage admin
+ * @copyright  2014 Frédéric Massart - FMCorz.net
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class admin_setting_special_backup_auto_destination extends admin_setting_configdirectory {
+
+    /**
+     * Calls parent::__construct with specific arguments.
+     */
+    public function __construct() {
+        parent::__construct('backup/backup_auto_destination', new lang_string('saveto'), new lang_string('backupsavetohelp'), '');
+    }
+
+    /**
+     * Check if the directory must be set, depending on backup/backup_auto_storage.
+     *
+     * Note: backup/backup_auto_storage must be specified BEFORE this setting otherwise
+     * there will be conflicts if this validation happens before the other one.
+     *
+     * @param string $data Form data.
+     * @return string Empty when no errors.
+     */
+    public function write_setting($data) {
+        $storage = (int) get_config('backup', 'backup_auto_storage');
+        if ($storage !== 0) {
+            if (empty($data) || !file_exists($data) || !is_dir($data) || !is_writable($data) ) {
+                // The directory must exist and be writable.
+                return get_string('backuperrorinvaliddestination');
+            }
+        }
+        return parent::write_setting($data);
+    }
+}
+
 
 /**
  * Special debug setting
diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 70a96d10d57..5c628bf1517 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -4121,6 +4121,23 @@ function xmldb_main_upgrade($oldversion) {
 
         // Main savepoint reached.
         upgrade_main_savepoint(true, 2015010800.01);
+
+    }
+
+    if ($oldversion < 2015011501.02) {
+
+        // If the site is using internal and external storage, or just external
+        // storage, and the external path specified is empty we change the setting
+        // to internal only. That is how the backup code is handling this
+        // misconfiguration.
+        $storage = (int) get_config('backup_auto_storage', 'backup');
+        $folder = get_config('backup_auto_destination', 'backup');
+        if ($storage !== 0 && empty($folder)) {
+            set_config('backup_auto_storage', 0, 'backup');
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2015011501.02);
     }
 
     return true;
diff --git a/version.php b/version.php
index 3499cfbbc37..eced7165e55 100644
--- a/version.php
+++ b/version.php
@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2015012300.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2015012600.00;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.