shield error uploading the payload

Been trying to upload a rev shell to wordpress, but I’m having some trouble. Tried both with MSF console and wp_admin_shell_upload and with the web interface, uploading a plugin file and a theme file, but the upload never finishes. On MSF I got the error:

[-] Exploit aborted due to failure: unexpected-reply: Failed to upload the payload

When I enable httptrace, i notice that specifically the request:

POST /wordpress/wp-admin/update.php?action=upload-plugin HTTP/1.1

Doesn’t get any response.

At first I thought that could be something someone has done to the machine, but this happen even when i restart it.

Don’t know what could it be. Any thoughts?