mogenshoj

There’s a bug causing media uploads not to work when you limit their access to the admin area.

Here’s how to fix it (tested in WP 3.6):
Open file wpuf.php and goto line 173 – looks like this:
$valid_pages = array('admin-ajax.php', 'async-upload.php', 'media-upload.php');

Below that add:

if (!current_user_can('edit_post')) {
    $user = new WP_User(get_current_user_id());
    $user->add_cap('edit_post');
    $user->add_cap('edit_others_pages');
    $user->add_cap('edit_published_pages');
}

Then the user will get the capabilities to upload media files, even if you limit their access to the admin area.