Symptoms
-
Unable to install or update license in Plesk by going to Tools & Settings > License Information > Install Key, because the following error shows up in the Plesk GUI:
Could not update the license. Make sure that connections to the license server ka.plesk.com on TCP port 443 are not blocked. See how to do so.
-
Errors that are similar to the following are recorded in
/var/log/plesk/panel.log
:[2023-04-09 13:36:05.641] 2629852:6432f779458e7 ERR [panel] KA Request Failure code: 2 Network failure
[2023-04-09 13:36:05.641] 2629852:6432f779458e7 ERR [panel] KA Request Failure desc: cURL cannot communicate with license server https://id-00.kaid.plesk.com:443/ (127.0.0.1): SSL connect error(35)
cURL cannot communicate with license server https://id-00.kaid.plesk.com:443/ (): Couldn't resolve host name(6)
[2023-04-09 13:36:05.641] 2629852:6432f779458e7 ERR [panel] KA Request Failure additional information: cURL verbose output:
About to connect() to id-00.kaid.plesk.com port 443 (#0)
Trying 127.0.0.1…
Connected to id-00.kaid.plesk.com (127.0.0.1) port 443 (#0)
Initializing NSS with certpath: sql:/etc/pki/nssdb
NSS error -12263 (SSLERRORRXRECORDTOO_LONG)
SSL received a record that exceeded the maximum permissible length.
Closing connection 0cURL verbose output:
Could not resolve host: id-00.kaid.plesk.com; Name or service not known
Closing connection 1 - After license activation, wrong Key Number is shown is Plesk > Tools & Settings > License Information.
Cause
Plesk KA (Key Adminstrator) server IPs are defined and incorrectly assigned to localhost IPs (or other incorrect IPs) in the /etc/hosts
file of the server, for example:
# root @server in ~: cat /etc/hosts
203.0.113.2 ka.plesk.com
127.0.0.1 id-b1.kaid.plesk.com ka.plesk.com leika.plesk.com id-00.kaid.plesk.com id-01.kaid.plesk.com
Resolution
-
Connect to the server via SSH
-
Edit the
/etc/hosts
file with your favorite command-line text editor -
Remove the KA Server lines entirely (or comment them by placing a
#
symbol at the start of each such line) - Save the changes and close the file
Afterwards, you should be able to repeat the Plesk license installation or update action via the Plesk GUI without encountering errors.