Unable to connect Plesk server to Plesk 360 and install 360 Monitoring: The server is misconfigured and cannot be added

Symptoms

• Unable to connect Plesk server to Plesk 360 and install 360 Monitoring either via Plesk interface or CLI:

  PLESK_WARN: The server is misconfigured and cannot be added. Please contact support.

• Following error message can be found in the Plesk panel.log with debug enabled:

  CONFIG_TEXT: JsonException: Malformed UTF-8 characters, possibly incorrectly encoded

• Connect to Plesk 360 via CLI may produce the following error:

  CONFIG_TEXT: Request failed: `POST https://dashboard.webpros.com/api/v1/si/servers/challenge` resulted in a `400 Bad Request` response

Cause

Plesk 360 extension bug.

Resolution

1. Connect to the server via SSH.

2. Run the next command:

   # plesk ext platform360 --events-key -regenerate

3. Proceed with connection and activation of 360 Monitoring.

Note: In case only a connection to Plesk 360 is required, then proceed with the connection step only.