Website hosted in Plesk shows 500 error: Provider cannot be found. It may not be properly installed.

Symptoms

• Website hosted on Plesk does not work:

  CONFIG_TEXT: Internal Server Error 500

  ---

  CONFIG_TEXT: The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine.

  ---

  CONFIG_TEXT: HTTP Error 500.0 - ASP.NET Core IIS hosting failure (in-process)

• While accessing website directly from the server shows:

  CONFIG_TEXT: Could not load file or assembly 'XXXXX' or one of its dependencies

  ---

  CONFIG_TEXT: Assembly binding logging is turned OFF

• Enabled Failed request tracing shows the following:
  

  CONFIG_TEXT: Provider cannot be found. It may not be properly installed.

  CONFIG_TEXT: ModuleName IsapiModule
  Notification EXECUTE_REQUEST_HANDLER
  HttpStatus 500
  HttpReason Internal Server Error

  ---

  CONFIG_TEXT: The requested resource is in use (0x800700aa)

Cause

32-bit application mode is disabled in application pool settings.

Resolution

1. Log in to Plesk
2. Go to Domains > example.com > Dedicated IIS Application Pool for Website
3. Check the checkbox Enable 32-bit applications and click OK