Hi
I am getting some errors after activating this plugin, on the next page at /wp-admin/. The errors are on line 232 of download-manager.php and line 30 and 4 of wpdm-server-file-browser.php.
In both cases, there's an if for $GET['task']. This key is not present in the get array at this point. I fixed it locally using if(array_key_exists('task',$_GET)).
I encountered further errors which caused me to wrap the following blocks of code in a if(array_key_exists('dir',$_POST)); although, at this point, I'm not sure if this will still allow the plugin to operate correctly