Final update:

nonwithstanding the fact the reCaptcha module is not installed and the backup i have restored is prior to this module installation, when everything was working just fine, the upgrade resulted in the deadly SiteSettings unavailable message: here is the log detail..

ModuleId: 422
ModuleDefId: 14
FriendlyName: Site Settings
ModuleControlSource: DesktopModules/Admin/Portals/SiteSettings.ascx
AssemblyVersion: 6.2.9
PortalID: 3
PortalName: MY PORTAL NAME
UserID: 1
UserName: host
ActiveTabID: 90
ActiveTabName: Site Settings
RawURL: /Admin/SiteSettings/tabid/90/language/en-US/Default.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: http://www.xxxxxxx.xxx/Admin/SiteSett...
UserAgent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 8b4daabc-67f0-4416-9e8d-5d135e371c65
InnerException: Object reference not set to an instance of an object.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: DotNetNuke.Modules.Admin.Portals.SiteSettings.UpdatePortal
StackTrace:
Message: DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Modules.Admin.Portals.SiteSettings.UpdatePortal(Object sender, EventArgs e) --- End of inner exception stack trace ---
Source:
Server Name: websv08

URGENT HELP WANTED WITH THIS ISSUE!!
Is there a way I can fix this?? Site settings is where evertything basically happens! If this part doesn't work my portals are almost read-only....:/ not much I can change except the content - unless other modules start randomly throwing exceptions!
Is there a way I can update the site setting someplace else?

First of all, thank you for the answer

Is there a way to do that with the Site Settings page not working? i.e. via database or something or do I have to:
restore che backup,
make and save the change,
make another copy of the installation files (8+ gigs)
Upgrade and see if it works?
Thanks

Of course you can do that in the database as well, if your Host :: SQL page works. Enter

   UPDATE {databaseOwner}{objectQualifier}HostSettings
   SET SettingValue='P'
   WHERE SettingName='PageStatePersister'

You have to restart the application pool after this change to take effect.

Happy DNNing!
Michael

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