The Event Post map issue in browsers (Chrome, Firefox, IE)

I am getting an error “net::ERR_INSECURE_RESPONSE” in the Chrome console and an error “Error: WebGL warning: Failed to create WebGL context: failIfMajorPerformanceCaveat: Driver is not hardware-accelerated.” in Firefox. There is some issue with Openlayers.js. You can see icon map, but no map landscape.