Hi Willem Jan you can run your local model on https running a simple service like this: https://github.com/cameronhunter/local-ssl-proxy
make sure you have installed node.js before you can run this.
Don't know if it solves directly your problem but give it a try :)
I tried to run with https using IIS and rewrite options but that did not solve the issue. I looked at the JAVA code anf figured out https is not registered when checking 'Skip connection check' in the iDEAL settings -> Acceptant. I had this option checked due to an error I get regarding the connection...
com.mendix.modules.microflowengine.MicroflowException: com.mendix.core.CoreRuntimeException: com.mendix.systemwideinterfaces.MendixRuntimeException: javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated at iDEAL.DoIssuerRequest (JavaAction : 'XMLMessageSend')
So somehow it looks like I have an authentication error. I have uploaded all certificates as supplied by the simulator.
Any hints welcome, thanks!
After some trial and error I have figured out the solution which was setting the java version to 1.8. Many articles mention the change between Java versions 7 and 8 when handling SSL stuff.
My local environment uses Java 8 now. For Mendix runtime v4 I guess they are also running Java 8. From the admin site the option to switch between Java version is gone. Mendix runtime V3 still has the choice of Java version and there I select version 8 as well.
For now just happy to have this running.