if you don't see "shared domains" under domains/subdomain manager, then that mean you don't have any subdomain register, it also means your subdomain http://www.membersarea.50webs.com had been deleted, it doesn't matter you have folder called /membersarea.50webs.com/ in files manager but there is not subdomain, it won't work, as far I check the subdomain http://www.membersarea.50webs.com is not registered...
That is correct, the hostname membersarea.50webs.com is not registered.
We have divided the FREE plan hostnames to several IPs. Now if some host receive flood attack, only the connected hostnames with the same IP will be down, until we take control under the attack.
Currently all hostnames are back online and works fine.
I can login OK to my file manager and view pages there. But linking to my site via the online URL (such as given in your post) gives that error message... ? ?