Plesk ASP site shows 500 error: Operation is not allowed when the object is closed

Symptoms

• ASP site hosted in Plesk shows:

  CONFIG_TEXT: 500 Internal server error.

• The following error can be found in Plesk > Domains > example.com > Logs:

  CONFIG_TEXT: GET / |198|800a0e78|Operation_is_not_allowed_when_the_object_is_closed. HTTP/1.1

• The following error can be found in Failed Request Tracing for a site:

  CONFIG_TEXT: 413. -ASP_LOG_ERROR
  LineNumber    198
  ErrorCode    800a0e78
  Description    Operation is not allowed when the object is closed.
  416. -MODULE_SET_RESPONSE_ERROR_STATUS
  ModuleName    IsapiModule
  Notification    EXECUTE_REQUEST_HANDLER
  HttpStatus    500
  HttpReason    Internal Server Error
  HttpSubStatus    0
  ErrorCode    The operation completed successfully.

Cause

Incorrect connection settings to the database server.

If the opening of the connection fails, the server continues processing code because the connection was opened. Thus operations on a closed object are performed.

Resolution

Generally, this issue is related to website coding or incorrect ASP.Net configuration/mappings.

• Change the website code to include the correct connection settings.

• Install the necessary ASP.NET version according to the Microsoft documentation.

• Make sure that all the requirements necessary for the website are met in the system.