diff --git a/src/Database/Database.php b/src/Database/Database.php
index d3ec4d585a..d13b52848d 100644
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -4,6 +4,7 @@ namespace Friendica\Database;
 
 use Friendica\Core\Config\Cache\ConfigCache;
 use Friendica\Core\System;
+use Friendica\Network\HTTPException\InternalServerErrorException;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Profiler;
 use mysqli;
@@ -126,7 +127,7 @@ class Database
 				$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 				$this->connected = true;
 			} catch (PDOException $e) {
-				/// @TODO At least log exception, don't ignore it!
+				$this->connected = false;
 			}
 		}
 
@@ -484,6 +485,10 @@ class Database
 		// We are having an own error logging in the function "e"
 		$called_from_e = ($called_from['function'] == 'e');
 
+		if (!isset($this->connection)) {
+			throw new InternalServerErrorException('The Connection is empty, although connected is set true.');
+		}
+
 		switch ($this->driver) {
 			case 'pdo':
 				// If there are no arguments we use "query"
diff --git a/src/Model/Contact.php b/src/Model/Contact.php
index 6f9ee4cdb6..14f970e593 100644
--- a/src/Model/Contact.php
+++ b/src/Model/Contact.php
@@ -1795,13 +1795,19 @@ class Contact extends BaseObject
         /**
 	 * @brief Helper function for "updateFromProbe". Updates personal and public contact
 	 *
-	 * @param array $contact The personal contact entry
-	 * @param array $fields  The fields that are updated
+	 * @param integer $id      contact id
+	 * @param integer $uid     user id
+	 * @param string  $url     The profile URL of the contact
+	 * @param array   $fields  The fields that are updated
+	 *
 	 * @throws \Exception
 	 */
 	private static function updateContact($id, $uid, $url, array $fields)
 	{
-		DBA::update('contact', $fields, ['id' => $id]);
+		if (!DBA::update('contact', $fields, ['id' => $id])) {
+			Logger::info('Couldn\'t update contact.', ['id' => $id, 'fields' => $fields]);
+			return;
+		}
 
 		// Search for duplicated contacts and get rid of them
 		if (self::handleDuplicates(Strings::normaliseLink($url), $uid, $id) || ($uid != 0)) {
@@ -1814,6 +1820,11 @@ class Contact extends BaseObject
 		// Archive or unarchive the contact. We only need to do this for the public contact.
 		// The archive/unarchive function will update the personal contacts by themselves.
 		$contact = DBA::selectFirst('contact', [], ['id' => $id]);
+		if (!DBA::isResult($contact)) {
+			Logger::info('Couldn\'t select contact for archival.', ['id' => $id]);
+			return;
+		}
+
 		if (!empty($fields['success_update'])) {
 			self::unmarkForArchival($contact);
 		} elseif (!empty($fields['failure_update'])) {