HTTP status and sub-status codes provide valuable information about the issues users come across. One of the code pairs is 500.19 which means “Configuration data is invalid“. However, IIS may show this pair incorrectly if a user drops connection before the browser loads the website completely.
The error message from the Failed Request Tracing log is below. Please note that this error appears during the execution of the Dynamic Compression module.
HttpReason: Internal Server Error
ErrorCode: An operation was attempted on a non existent network connection (0x800704cd)