Merge branch '6.4RC'6.4

1 files changed, 1 insertions, 1 deletions

diff --git a/library/jsonld/jsonld.php b/library/jsonld/jsonld.php
index 8cd3e7ceb..bc3ca7a31 100644
--- a/library/jsonld/jsonld.php
+++ b/library/jsonld/jsonld.php
@@ -449,7 +449,7 @@ function jsonld_default_secure_document_loader($url) {
   $result = @file_get_contents($url, false, $context);
   if($result === false) {
     throw new JsonLdException(
-      'Could not retrieve a JSON-LD document from the URL: ' + $url,
+      'Could not retrieve a JSON-LD document from the URL: ' . $url,
       'jsonld.LoadDocumentError', 'loading document failed');
   }
   $link_header = array();