hello
I was preparing the server in remote location for deployment so..
i set up the server locally on my subnet and i accessed plesk panel using a laptop on the same subnet
so server ip was 192.168.2.52 computer 192.168.2.10
anyway the link when i was previewing the site was pointing i forget exact path to
http://192.168.2.52/plesk-site-preview/domainname.com/192.168.2.52/ something like that
and we getting that error then..
i never figured out why the preview did not work...
but
i deployed the server in server room today
and previews dont work but i dont care now... however it would be nice to fix it
once the server went live i could access these servers from outside and pages displayed correctly, websites work and same domains are access-able .
So conclusion in my case is that something got screwed up with latest plesk 12.5 preview ( previous builds from about 2 months ago worked just fine on local subnet ) and do not work on local subnet and they used to. However they work when accessed from outside internet.
I would think it has to do with plesk own permissions accessing their own folder while trying to do previews.
i attached a pic of Preview Button that was causing issue.