Hi Doug,
you can try to increase the log level for certain http/https related log factories in the Server logger configuration in IS Admin to check if there might some messages.
But if you really receive an http error “500 Internal Server Error”, this means that the technical connection between you and your partner was successful, but something in their processing went wrong. These messages should be in server log on their side.
Regards,
Holger
#Integration-Server-and-ESB#webMethods#webmethods-Protocol-and-Transport