Starting with SVN revision 5224 (and finalized in revision 5226), TIdHTTP now has new functionality that allows it to auto-create an internal default SSLIOHandler object when requesting an HTTPS url if no IOHandler has been assigned yet. If you need to customize the SSLVersions used, or specify certificates/keys, or use status/password event handlers, then you will still have to explicitly assign an SSLIOHandler component to the TIdHTTP.IOHandler property before sending an HTTPS request. However, for simplier scenarios that do not require customizing, TIdHTTP can now create its own SSLIOHandler object with a default configuration (eg, TLSv1) if it needs to. This helps to avoid the EIdIOHandlerPropInvalid exception when no SSLIOHandler is available, and makes TIdHTTP a little easier to use “out of the box”. The catch, however, is that you still need to explicitly specify the desired SSLIOHandler unit in your uses clause so that the SSLIOHandler class can register itself for use with this new mechanism.