Have you tried a different browser? Do you get a page not found, a HTTP error code, or simply the LAMS community login page?
If you only get the LAMS Community login page, with IE you might have to change the setting to allow third party cookies (LAMS Community would be the 3rd party here since you are on your LAMS website). The option to change this is in Tools->Options->Privacy->Advanced.
The community website URL is in the configuration_items table in the database, is it possible this parameter was changed on your LAMS server?
Posted by Jun-Dir Liew