diff --git a/src/Content/Text/HTML.php b/src/Content/Text/HTML.php
index 276094a8f9..adfc60eae1 100644
--- a/src/Content/Text/HTML.php
+++ b/src/Content/Text/HTML.php
@@ -180,7 +180,9 @@ class HTML
 		$xpath = new DomXPath($doc);
 		$list = $xpath->query("//pre");
 		foreach ($list as $node) {
-			$node->nodeValue = str_replace("\n", "\r", $node->nodeValue);
+			// Ensure to escape unescaped & - they will otherwise raise a warning
+			$safe_value = preg_replace('/&(?!\w+;)/', '&', $node->nodeValue);
+			$node->nodeValue = str_replace("\n", "\r", $safe_value);
 		}
 
 		$message = $doc->saveHTML();
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index d2f5b3b2d5..1a631496b9 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -329,6 +329,11 @@ class Processor
 			return;
 		}
 
+		if (empty($object['id'])) {
+			Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
+			return;
+		}
+
 		$activity = [];
 		$activity['@context'] = $object['@context'];
 		unset($object['@context']);