Unable to access/activate Plesk Onyx: The license key is invalid. In order to use the Panel, you need to obtain and install a new valid license key

Symptoms

• Plesk cannot be accessed/activated

  One of the following errors on web browser screen:

  PLESK_ERROR: Error: The license key is invalid. In order to use the Panel, you need to obtain and install a new valid license key. The amount of currently used resources overrides the limits defined by your license.

  OR

  xmlrpc error: Expected <param> to have 1 children, found 0
   ---------------------- Debug Info -------------------------------
   0: common_func.php3:4675
   of_get_all_keys()
   1: common_func.php3:4675
   pkey_fetch_key_list()
   2: KeyInfoForm.php:171
   KeyInfoForm->get_bye_online_url(string 'new', string '')
   3: KeyInfoForm.php:77
   KeyInfoForm->assign()
   4: key_info.php:43
   require(string 'C:Program FilesParallelsPleskadminhtdocsserverkey_info.php')
   5: plesk.php:66

  OR

  ERROR: SWKeyExFatalError

  OR

  xmlrpc error: XML parsing failed
   0: common_func.php3:4523
   of_get_key_by_product(string 'plesk-win')
   1: common_func.php3:4523
   getPleskKey()
   2: common_func.php3:4602
   getKeyProp(string 'demo')
   3: auth.php3:54

  OR

  Internal error:
   Reposit…