I'm using OpenCart 1.5.6.4 and Product Downloads PRO 4.0.5 extension. My Operating System is Windows 7 and local virtual server is OpenServer.
Product Downloads PRO extension settings are default.
Does not work uploading files on Catalog->Downloads->Downloads->Insert (.../admin/index.php?route=catalog/download_ext/insert&token=...)
When I click on the "+ Add files ..." button, I select a file and try to upload it by clicking on "Upload", I get a Forbidden error related to the lack of access to the /system/library/upload.php file:



The extension of the uploading file does not matter.
The ./admin/index.php?route=catalog/download_ext/insert page corresponds to the ./admin/controller/catalog/download_ext.php controller, which displays ./admin/view/template/catalog/download_ext_form.tpl view.
The '/system/library/upload.php' path is passed from the controller to the view via the variable $this-> data ['upload']:

The value of the $upload variable is displayed in a view in a minified js script:

For the first time I see such file calling:
$this->data['upload'] = HTTPS_CATALOG . 'system/library/upload.php?token=' . $this->session->data['token'];
The requested file is not a controller. How can it be called?
Most likely, the problem is not in the upload.php file , but in the system/ or system/library/ folder, to which access is denied.
Let's do a little experiment. Change the name of the file to an arbitrary file (for example, to aaa.php) and try to upload the file again. We again get the error "Forbidden", despite the fact that such a file does not even exist:


How do I fix files uploading?