diff --git a/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php b/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php
index f6acbbb..b6bb75d 100644
--- a/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php
+++ b/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php
@@ -61,7 +61,7 @@ protected static function getUriAsDisplayableString($uri) {
 
     if ($scheme === 'user-path') {
       $uri_reference = ltrim(explode(':', $uri, 2)[1], '/');
-      if (!in_array($uri_reference[0], ['?', '#', '/'])) {
+      if ($uri_reference && !in_array($uri_reference[0], ['?', '#', '/'])) {
         $uri_reference = '/' . $uri_reference;
       }
     }