Plesk the license key has expired.

Error:

The amount of Plesk Control Panel resources you operate with has exceeded the limits defined by your current product license. Please contact Parallels sales department in order to purchase a new licensed key.
OR
The amount of Plesk resources you operate with has exceeded the limits defined by your current product license. Please contact SWsoft, Inc. sales department in order to purchase a new licensed key
OR
the license key has expiered. please contact your service provider
Resolution:

Symptoms
Plesk cannot retrieve license key. The following error appears:

Key Update Status:
Unable to update Plesk Key. An error occurred while processing your key.

You can try to update it later. The key cannot be upgraded due to the network failure during connection with the Key Authority server. Please check that your Internet connection is configured, you can resolve and access ka.swsoft.com and your firewall enables outgoing connections to TCP port 5224.

However it is possible to telnet to ka.swsoft.com on port 5224.
Cause
When Plesk sends request to KA server it generates special XML packet. Data for this packet is taken from Plesk database `key_history` table.

In case the data is corrupted it cannot be retrieved.

Example of corrupted records in MySQL database:

mysql> select id, plesk_key_id from key_history;

+----+------------------------------------------------------------+ 

| id | plesk_key_id                                                          

+----+------------------------------------------------------------+ 

|  1 | plsk000000000000                                               

|  2 | ?^uxi~Lг¦--¬a°Nx-?L¦»<a;?г*f5>-??+?@t?¦b-+i¦ 

|  3 | ?^uxi~Lг¦--¬a°Nx-?L¦»<a;?г*f5>-??+?@t?¦b-+i¦ 

|  4 | PLSK005268120000                                           

|  5 | PLSK004332790001                                           

|  6 | PLSK004332790002                                           

+----+-----------------------------------------------------------+

6 rows in set (0.00 sec)

mysql>

Resolution
Records with ID 2 and 3 are corrupted. To fix the problem it is necessary to remove them. Use the following command to remove the problem records:

mysql> delete from key_history where id=2 or id=3;
Query OK, 2 rows affected(0.03 sec)

mysql>