Issue #3337496: From my log

src/TokenOrTokensPreAlter.php

@@ -32,7 +32,9 @@ class TokenOrTokensPreAlter {
   public function tokensPreAlter(&$text, $data, $options) {
     $matches = [];
 
-    preg_match_all("/\[[^\[\]]+\]/", $text, $matches);
+    if (is_string($text)) {
+      preg_match_all("/\[[^\[\]]+\]/", $text, $matches);
+    }
 
     if (empty($matches)) {
       return;