Frequent reactivation prompts in IntelliJ IDEA – Support | JetBrains

Problem

Users experience frequent reactivation prompts (every 3 to 10 minutes) when using IntelliJ IDEA with both KeyCloak and LDAP authentication. Additionally, license connections are intermittently lost during workdays.

Cause

The problem was caused by port contention on Windows systems. When the IntelliJ IDEA tries to open a LISTEN connection on port 62345 for license activation, it fails if the port is already reserved or excluded by Windows’ configuration. The failure results in reactivation errors. This issue is observable regardless of the authentication provider (KeyCloak or LDAP).

Example check for reserved ports:

netsh int ipv4 show excludedportrange protocol=tcp

Output:

Starting Port    Ending Port
-------------    ------------
80               80
6065             6065
7268             7268
7658             7658
50000            50059
62339            62438
62523            62622

In this case, port 62345 falls within the excluded range, causing the failure.

Resolution

Verify if the problematic port (62345 in this case) is within the excluded ranges on the affected systems by running the PowerShell command:
```
netsh int ipv4 show excludedportrange protocol=tcp
```
If the port is within the excluded range, reconfigure the Windows system to free the port or configure the IntelliJ IDEA settings to use a non-conflicting port.
Reboot the affected Windows machine after making configuration adjustments to apply changes.
Ensure the issue is resolved and users no longer experience reactivation errors.

For further assistance, consult the system administrators to adjust the Windows configuration as necessary.