- A country blocking firewall rule blocks connection to ka.plesk.com
- The product license fails to update. The following errors may occur:
PLESK_ERROR: Licensing Server Unreachable: Unable to connect with licensing server.
Please make sure that your network allows communication to ka.plesk.com:5224.
For more details check system help pages.
PLESK_ERROR: Couldn't resolve host name
PLESK_ERROR: Can't connect to ka.plesk.com:5224 (Timeout)
- Plesk is not accessible:
PLESK_ERROR: Error: The license key is invalid. in order to use Plesk, please obtain and install a new valid license key.
Your license key has expired. To continue using your Plesk, you must purchase a non-expiring commercial license key.
- The following error is shown when trying to activate license at Tools & Settings > License Management > Install Key:
PLESK_ERROR: Not valid XML. Invalid XML "content". Problem with token at '\n \n\n
Plesk tries to connect to the license server
on TCP port 5224 to update the license, but cannot establish connection.
Since February 5, 2018 , ka.plesk.com hostname will be resolved into 3 different IP addresses based on round-robin logic:
- 18.104.22.168 (old one)
- 22.214.171.124 ( new )
- 126.96.36.199 ( new )
Additionally, since the same date, the Key Administrator will accept connections from Plesk on two ports :
- 5224 (old one, non-standard port)
- 443 (new, the default HTTPS port)
Make sure that Plesk is able to establish connection to all three Key Administrator IP addresses and both Key Administrator ports in all their combinations (see the table below):
# ping ka.plesk.com
# telnet ka.plesk.com 5224
If the license server does not resolve into the correct IPs, check the
In case any of these servers are behind a firewall and old IP addresses of Key Administrator are listed in the firewall rules, please add new IP addresses of the Key Administrator to the firewall rules before February 1, 2018 to allow your servers to connect to
. This can be checked with these commands, depending on your OS:
# nmap -P0 -p5224 ka.plesk.com
# telnet ka.plesk.com 5224
# traceroute ka.plesk.com
telnet ka.plesk.com 5224
Note: Telnet client should be installed additionally for Windows -> how to install Telnet client
If APF firewall is used, check
for the mentioned IPs or the hostname
As temporary workaround, upload a file with license to the server and install it from a command line (command is applicable for both: Windows and Linux):
# plesk bin license -i path_to_license_file
Note: License will be broken after next Daily Maintenance Task execution.
If you use any of the following product versions:
- Plesk for Linux 7.1-8.2.1
- Sitebuiler for Linux 1.x-2.1.3
and have issues with license update , refer to this article:
- 213404169 License fails to update or upgrade (legacy product versions)
If the license fails to update on Plesk for Windows 7.5 - 8.x installed on Windows XP/Windows Server 2003 (Microsoft Windows 5.2) , see more details in article
- 213377529 License for Plesk 7.5/7.6 or 8.x for Windows fails to update