diff --git a/backup/backup.php b/backup/backup.php
index 1c1cf29f6c1..0f3bf7add3f 100644
--- a/backup/backup.php
+++ b/backup/backup.php
@@ -130,6 +130,13 @@ if ($backup->get_stage() == backup_ui::STAGE_FINAL) {
     // Carry out actual backup.
     $backup->execute();
 
+    // Backup controller gets saved/loaded so the logger object changes and we
+    // have to retrieve it.
+    $logger = $backup->get_controller()->get_logger();
+    while (!is_a($logger, 'core_backup_html_logger')) {
+        $logger = $logger->get_next();
+    }
+
     // Get HTML from logger.
     $loghtml = $logger->get_html();
 
diff --git a/backup/moodle2/backup_custom_fields.php b/backup/moodle2/backup_custom_fields.php
index 12929de6578..b5c32a5e84b 100644
--- a/backup/moodle2/backup_custom_fields.php
+++ b/backup/moodle2/backup_custom_fields.php
@@ -107,7 +107,19 @@ class file_nested_element extends backup_nested_element {
             backup_file_manager::copy_file_moodle2backup($this->backupid, $values);
         } catch (file_exception $e) {
             $this->add_result(array('missing_files_in_pool' => true));
-            $this->add_log('missing file in pool: ' . $e->debuginfo, backup::LOG_WARNING);
+
+            // Build helpful log message with all information necessary to identify
+            // file location.
+            $context = context::instance_by_id($values->contextid, IGNORE_MISSING);
+            $contextname = '';
+            if ($context) {
+                $contextname = ' \'' . $context->get_context_name() . '\'';
+            }
+            $message = 'Missing file in pool: ' . $values->filepath  . $values->filename .
+                    ' (context ' . $values->contextid . $contextname . ', component ' .
+                    $values->component . ', filearea ' . $values->filearea . ', itemid ' .
+                    $values->itemid . ') [' . $e->debuginfo . ']';
+            $this->add_log($message, backup::LOG_WARNING);
         }
     }
 }
diff --git a/backup/util/dbops/restore_dbops.class.php b/backup/util/dbops/restore_dbops.class.php
index a6d5bce169f..00fb8f3616f 100644
--- a/backup/util/dbops/restore_dbops.class.php
+++ b/backup/util/dbops/restore_dbops.class.php
@@ -995,11 +995,7 @@ abstract class restore_dbops {
                 if ($includesfiles) {
                     // The file is not found in the backup.
                     if (!file_exists($backuppath)) {
-                        $result = new stdClass();
-                        $result->code = 'file_missing_in_backup';
-                        $result->message = sprintf('missing file %s%s in backup', $file->filepath, $file->filename);
-                        $result->level = backup::LOG_WARNING;
-                        $results[] = $result;
+                        $results[] = self::get_missing_file_result($file);
                         continue;
                     }
 
@@ -1028,11 +1024,7 @@ abstract class restore_dbops {
                             $fs->create_file_from_storedfile($file_record, $foundfile->id);
                         } else {
                             // A matching existing file record was not found in the database.
-                            $result = new stdClass();
-                            $result->code = 'file_missing_in_backup';
-                            $result->message = sprintf('missing file %s%s in backup', $file->filepath, $file->filename);
-                            $result->level = backup::LOG_WARNING;
-                            $results[] = $result;
+                            $results[] = self::get_missing_file_result($file);
                             continue;
                         }
                     }
@@ -1063,6 +1055,22 @@ abstract class restore_dbops {
         return $results;
     }
 
+    /**
+     * Returns suitable entry to include in log when there is a missing file.
+     *
+     * @param stdClass $file File definition
+     * @return stdClass Log entry
+     */
+    protected static function get_missing_file_result($file) {
+        $result = new stdClass();
+        $result->code = 'file_missing_in_backup';
+        $result->message = 'Missing file in backup: ' . $file->filepath  . $file->filename .
+                ' (old context ' . $file->contextid . ', component ' . $file->component .
+                ', filearea ' . $file->filearea . ', old itemid ' . $file->itemid . ')';
+        $result->level = backup::LOG_WARNING;
+        return $result;
+    }
+
     /**
      * Given one restoreid, create in DB all the users present
      * in backup_ids having newitemid = 0, as far as