Plesk interface is unavailable: "The identity of application pool PleskControlPanel is invalid" or "PR_CONNECT_RESET_ERROR"

Symptoms

• Plesk is not accessible with one of the following error messages in a web browser:

  PLESK_INFO: HTTP Error 503. The service is unavailable.

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  PLESK_INFO: Secure Connection Failed
  Error code: PR_CONNECT_RESET_ERROR

• In Windows Event Viewer > Windows Logs > System, the following error and warnings are logged:

  PLESK_INFO: Application pool PleskControlPanel has been disabled. Windows Process Activation Service (WAS) encountered a failure when it started a worker process to serve the application pool.

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  PLESK_INFO: Application pool PleskControlPanel has been disabled. Windows Process Activation Service (WAS) did not create a worker process to serve the application pool because the application pool identity is invalid.

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  PLESK_INFO: The identity of application pool PleskControlPanel is invalid. The user name or password that is specified for the identity may be incorrect, or the user may not have batch logon rights. If the identity is not corrected, the application pool will be disabled when the application pool receives its first request. If batch logon rights are causing the problem, the identity in the IIS configuration store must be changed after rights have been granted before Windows Process Activation Service (WAS) can retry the logon. If the identity remains invalid after the first request for the application pool is processed, the application pool will be disabled. The data field contains the error number.

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  PLESK_INFO: A fatal alert was received from the remote endpoint. The TLS protocol defined fatal alert code is 46.

• In IIS Manager > Application Pools > right-click on PleskControlPanel > Advanced Settings > Process Model, Identity is configured correctly with built-in account ApplicationPoolIdentity.

• In IIS Manager > Application Pools > PleskControlPanel, when clicking Start the operation will succeced, but as soon as there is an attempt to access Plesk, the application pool crashes with the previous error messages.

Cause

IIS malfunction.

Resolution

1. Connect to your Plesk server via RDP.

2. Go to IIS > Sites > Right-click on pleskcontrolpanel > Remove.

3. Go to IIS > Application Pools > Right-click on PleskControlPanel > Remove.

4. Start a command prompt as Administrator.

5. Recreate PleskControlPanel site and its application pool:

   C:\> "%plesk_bin64%\websrvmng.exe" --configure-plesk-website

6. Restart IIS service and try again:

   C:\> iisreset