The keyfiles need to be in the same directory as the Miami executable, NOT in "S:" or "L:" or "Envarc:" or "LIBS:".
Secondly, they must be correctly named and the right type of icon. The filenames must be correct and are case sensitive, as follows:
Miami.key1
Miami.key2
Also, MiamiSSL will refuse to install in demo mode, so you need to get the keys right before SSL will work. When you do get it going, for SSL to work you need to have the encryption library installed in "Miami:Libs", NOT "Sys:Libs".