diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Base/DateTimeHelper.php b/snappymail/v/0.0.0/app/libraries/MailSo/Base/DateTimeHelper.php
index 826b3bd26..b02b5ee0e 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Base/DateTimeHelper.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Base/DateTimeHelper.php
@@ -43,7 +43,7 @@ abstract class DateTimeHelper
 		}
 
 		$sDateTime = \trim(\preg_replace('/ \([a-zA-Z0-9]+\)$/', '', $sDateTime));
-		$oDateTime = \DateTime::createFromFormat('D, d M Y H:i:s O', $sDateTime, \MailSo\Base\DateTimeHelper::GetUtcTimeZoneObject());
+		$oDateTime = \DateTime::createFromFormat(\DateTime::RFC822, $sDateTime, static::GetUtcTimeZoneObject());
 		return $oDateTime ? $oDateTime->getTimestamp() : 0;
 	}
 
@@ -61,10 +61,10 @@ abstract class DateTimeHelper
 
 		if (\preg_match('/^[a-z]{2,4}, /i', $sDateTime)) // RFC2822 ~ "Thu, 10 Jun 2010 08:58:33 -0700 (PDT)"
 		{
-			return \MailSo\Base\DateTimeHelper::ParseRFC2822DateString($sDateTime);
+			return static::ParseRFC2822DateString($sDateTime);
 		}
 
-		$oDateTime = \DateTime::createFromFormat('d-M-Y H:i:s O', $sDateTime, \MailSo\Base\DateTimeHelper::GetUtcTimeZoneObject());
+		$oDateTime = \DateTime::createFromFormat('d-M-Y H:i:s O', $sDateTime, static::GetUtcTimeZoneObject());
 		return $oDateTime ? $oDateTime->getTimestamp() : 0;
 	}
 
@@ -79,20 +79,21 @@ abstract class DateTimeHelper
 			return 0;
 		}
 
-		$oDateTime = \DateTime::createFromFormat('Y-m-d H:i:s O', $sDateTime, \MailSo\Base\DateTimeHelper::GetUtcTimeZoneObject());
+		$oDateTime = \DateTime::createFromFormat('Y-m-d H:i:s O', $sDateTime, static::GetUtcTimeZoneObject());
 		return $oDateTime ? $oDateTime->getTimestamp() : 0;
 	}
 
 	/**
 	 * Parse date string formated as "2015-05-08T14:32:18.483-07:00"
+	 * DateTime::RFC3339_EXTENDED
 	 */
 	public static function TryToParseSpecEtagFormat(string $sDateTime) : int
 	{
-		$sDateTime = \trim(\preg_replace('/ \([a-zA-Z0-9]+\)$/', '', \trim($sDateTime)));
-		$sDateTime = \trim(\preg_replace('/(:[\d]{2})\.[\d]{3}/', '$1', \trim($sDateTime)));
-		$sDateTime = \trim(\preg_replace('/(-[\d]{2})T([\d]{2}:)/', '$1 $2', \trim($sDateTime)));
-		$sDateTime = \trim(\preg_replace('/([\-+][\d]{2}):([\d]{2})$/', ' $1$2', \trim($sDateTime)));
+		$sDateTime = \preg_replace('/ \([a-zA-Z0-9]+\)$/', '', \trim($sDateTime));
+		$sDateTime = \preg_replace('/(:[\d]{2})\.[\d]{3}/', '$1', \trim($sDateTime));
+		$sDateTime = \preg_replace('/(-[\d]{2})T([\d]{2}:)/', '$1 $2', \trim($sDateTime));
+		$sDateTime = \preg_replace('/([\-+][\d]{2}):([\d]{2})$/', ' $1$2', \trim($sDateTime));
 
-		return \MailSo\Base\DateTimeHelper::ParseDateStringType1($sDateTime);
+		return static::ParseDateStringType1($sDateTime);
 	}
 }
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/AddressBook/CardDAV.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/AddressBook/CardDAV.php
index ae1422a0a..ab490fb49 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/AddressBook/CardDAV.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/AddressBook/CardDAV.php
@@ -27,6 +27,9 @@ trait CardDAV
 			$this->oLogger->WriteException($oException);
 		}
 
+		/**
+		 * find every <response><href>*.vcf</href> with empty <resourcetype/>
+		 */
 		if (\is_array($aResponse))
 		{
 			$mResult = array();
@@ -35,7 +38,6 @@ trait CardDAV
 				$sKey = \rtrim(\trim($sKey), '\\/');
 				if (!empty($sKey) && is_array($aItem))
 				{
-					$aItem = \array_change_key_case($aItem, \CASE_LOWER);
 					if (isset($aItem['{DAV:}getetag']))
 					{
 						$aMatch = array();
diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/dav/client.php b/snappymail/v/0.0.0/app/libraries/snappymail/dav/client.php
index 0ee873f4f..06ff9abc3 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/dav/client.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/dav/client.php
@@ -143,19 +143,21 @@ class Client
 			throw new \InvalidArgumentException('The passed data is not valid XML');
 		}
 
-		$ns = \array_search('urn:DAV', $responseXML->getNamespaces(true));
-		$ns = $ns ? "{$ns}:" : '';
+		$ns = \array_search('urn:DAV', $responseXML->getNamespaces(true)) ?: 'd';
 //		$ns_card = \array_search('urn:ietf:params:xml:ns:carddav', $responseXML->getNamespaces(true));
 
 		$result = array();
 
-		foreach ($responseXML->xpath("{$ns}response") as $response) {
-			$href = $response->xpath("{$ns}href");
+		$responseXML->registerXPathNamespace($ns, 'urn:DAV');
+		foreach ($responseXML->xpath("{$ns}:response") as $response) {
+			$response->registerXPathNamespace($ns, 'urn:DAV');
+			$href = $response->xpath("{$ns}:href");
 			$href = (string) $href[0];
 
 			$properties = array();
-			foreach ($response->xpath("{$ns}propstat") as $propStat) {
-				$status = $propStat->xpath("{$ns}status");
+			foreach ($response->xpath("{$ns}:propstat") as $propStat) {
+				$propStat->registerXPathNamespace($ns, 'urn:DAV');
+				$status = $propStat->xpath("{$ns}:status");
 				list($httpVersion, $statusCode, $message) = \explode(' ', (string)$status[0], 3);
 
 				$properties[$statusCode] = static::parseProperties(\dom_import_simplexml($propStat));