Can't install themes or upload images

I just installed WP following the guides, the WP is properly installed and working.

WP is installed in the root folder… /httpdocs

Now, when I try to upload an image or install a theme, I get the following message.

The uploaded file could not be moved to /var/www/vhosts/bydemian.com/httpdocs/wp-content/uploads.

I’ve checked the settings in media and it is OK so it is directed to wp-content/uploads any ideas how can I solve this?