diff --git a/dlf/plugins/oai/class.tx_dlf_oai.php b/dlf/plugins/oai/class.tx_dlf_oai.php
index 6f613e32..d010efa4 100644
--- a/dlf/plugins/oai/class.tx_dlf_oai.php
+++ b/dlf/plugins/oai/class.tx_dlf_oai.php
@@ -116,7 +116,7 @@ class tx_dlf_oai extends tx_dlf_plugin {
 
 		$this->error = TRUE;
 
-		$error = $this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/', 'error', $this->pi_getLL($type, $type, TRUE));
+		$error = $this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/', 'error', htmlspecialchars($this->pi_getLL($type, $type, FALSE), ENT_NOQUOTES, 'UTF-8'));
 
 		$error->setAttribute('code', $type);
 
@@ -342,16 +342,37 @@ class tx_dlf_oai extends tx_dlf_plugin {
 	 */
 	protected function getMetsData(array $metadata) {
 
+		$mets = NULL;
+
 		// Load METS file.
 		$xml = new DOMDocument();
 
-		$xml->load($metadata['location']);
+		if ($xml->load($metadata['location'])) {
 
-		// Get root element.
-		$root = $xml->getElementsByTagNameNS($this->formats['mets']['namespace'], 'mets');
+			// Get root element.
+			$root = $xml->getElementsByTagNameNS($this->formats['mets']['namespace'], 'mets');
 
-		// Import node into DOMDocument.
-		$mets = $this->oai->importNode($root->item(0), TRUE);
+			if ($root->item(0) instanceof DOMNode) {
+
+				// Import node into DOMDocument.
+				$mets = $this->oai->importNode($root->item(0), TRUE);
+
+			} else {
+
+				trigger_error('No METS node found in file "'.$location.'"', E_USER_ERROR);
+			}
+
+		} else {
+
+			trigger_error('Could not load file "'.$location.'"', E_USER_ERROR);
+
+		}
+
+		if ($mets === NULL) {
+
+			$mets = $this->oai->createElementNS('http://goobi.org/', 'goobi:error', htmlspecialchars($this->pi_getLL('error', 'Error!', FALSE), ENT_NOQUOTES, 'UTF-8'));
+
+		}
 
 		return $mets;
 
diff --git a/dlf/plugins/oai/locallang.xml b/dlf/plugins/oai/locallang.xml
index 596d6cce..9488c0bf 100644
--- a/dlf/plugins/oai/locallang.xml
+++ b/dlf/plugins/oai/locallang.xml
@@ -21,6 +21,7 @@
 			<label index="noRecordsMatch">The combination of the values of the from, until, set and metadataPrefix arguments results in an empty list.</label>
 			<label index="noMetadataFormats">There are no metadata formats available for the specified item.</label>
 			<label index="noSetHierarchy">The repository does not support sets or the value of the set argument is invalid.</label>
+			<label index="error">An error occured, please try again later. If this happens consistently, please contact the administrator.</label>
 		</languageKey>
 		<languageKey index="de" type="array">
 			<label index="tt_content.pi_flexform.sheet_general">Einstellungen</label>
@@ -38,6 +39,7 @@
 			<label index="noRecordsMatch">Die Anfrage ergab eine leere Treffermenge.</label>
 			<label index="noMetadataFormats">Für den gewünschten Datensatz werden keine Datenformate unterstützt.</label>
 			<label index="noSetHierarchy">Das Repository unterstützt keine Sets oder der Wert des Parameters "set" ist ungültig.</label>
+			<label index="error">Ein Fehler ist aufgetreten. Bitte versuchen Sie es später noch einmal. Sollte der Fehler dauerhaft auftreten, kontaktieren Sie bitte den Administrator.</label>
 		</languageKey>
 	</data>
 </T3locallang>
\ No newline at end of file