500 Internal Server Error of API Management Services (TLS Issues?)

api 500 API RP 500 Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division I. 500 series micinstrument preamp based on the 512c with added variable output level control and 3:1 output transformer tap selection.

api 500, 500 Internal Server Error 503 Service Unavailable.