Fixed assets path generation on windows (use server path for files where this is possible).

src/Services/Attachments/AttachmentURLGenerator.php

@@ -87,12 +87,13 @@ class AttachmentURLGenerator
      */
     public function absolutePathToAssetPath(string $absolute_path, ?string $public_path = null): ?string
     {
+        //Normalize file path (public path, use / as file path)
+        $absolute_path = str_replace('\\', '/', $absolute_path);
+
         if (null === $public_path) {
             $public_path = $this->public_path;
         }
 
-
-
         //Our absolute path must begin with public path or we can not use it for asset pathes.
         if (0 !== strpos($absolute_path, $public_path)) {
             return null;