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
Description Operation is not allowed when the object is closed.
HttpReason Internal Server Error
ErrorCode The operation completed successfully.
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.
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.