Apache httpd mod_ssl error "http request speaking HTTP to HTTPS port"

Issue

• We are seeing the following error in our ssl_error_log:

  [Mon Jan 05 15:57:29 2015] [info] SSL Library Error: 336027804 error:1407609C:SSL 
  routines:SSL23_GET_CLIENT_HELLO:http request speaking HTTP to HTTPS port!?
  

• Browser has returned "Bad Request" with the following message

  Your browser sent a request that this server could not understand.
  Reason: You're speaking plain HTTP to an SSL-enabled server port.
  Instead use the HTTPS scheme to access this URL, please.