Unable to install Plesk license: cURL cannot communicate with license server

Started by Suhitha, Sep 27, 2025, 08:23 AM

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Suhitha

Question: Unable to install Plesk license: cURL cannot communicate with license server


Symptoms

  • License installation on a Plesk server fails:

cURL cannot communicate with license server https://id-00.kaid.plesk.com:443/ (): Couldn't connect to server(7) cURL cannot communicate with license server https://id-00.kaid.plesk.com:443/ (): Couldn't resolve host name(6) (Error code: 2)


  • For Linux:

# host id-00.kaid.plesk.com
id-00.kaid.plesk.com is an alias for ka.plesk.com.
ka.plesk.com has address 195.214.233.82
ka.plesk.com has address 195.214.233.80
ka.plesk.com has address 195.214.233.81

  • For Windows:

c: /> nslookup id-00.kaid.plesk.com
Server:  UnKnown
Address:  2620:0:28a9:4::1
Non-authoritative answer:
Name:    ka.plesk.com
Addresses:  195.214.233.81
          195.214.233.80
          195.214.233.82
Aliases:  id-00.kaid.plesk.com

  • The connection to licensing servers fails:

# telnet ka.plesk.com 443
Trying 195.214.233.82...
telnet: Unable to connect to remote host: Connection refused

  • There are no blocking firewall rules for outbound traffic either in the local Firewall or in the external Firewall (if there is any)

  • Other operations on the server related to outgoing traffic, for example, packages installation or extensions catalog opening, fail as well
:

  • For Linux

# apt install nmap -y
..........
Err:1 http://archive.ubuntu.com/ubuntu xenial InRelease
Could not connect to archive.ubuntu.com:80 (203.0.113.2), - connection timed out [IP: 203.0.113.2 80]
..........
#wget https://ext.plesk.com
--2024-07-09 22:43:42-- https://ext.plesk.com/
Resolving ext.plesk.com (ext.plesk.com)... 79.127.235.11, 79.127.235.9, 79.127.213.245, ...
Connecting to ext.plesk.com (ext.plesk.com)|79.127.235.11|:443... connected.
WARNING: Could not save SSL session data for socket 3
Failed writing HTTP request: The specified session has been invalidated for some reason..
Retrying.
..........


For Windows:

c: /> curl https://ext.plesk.com
curl: (28) Failed to connect to ext.plesk.com port 443 after 21048 ms: Couldn't connect to server


Cause

Server-wide outgoing traffic issue. Most likely, issues on ISP/server provider side.


Resolution

Contact the ISP or server provider for further assistance.