APK compiled with JavaFXPorts does not work

I have been trying to get a sample HelloWorld JavaFX app to work on Android for a while. I have managed to get past all the dependency issues etc and have compiled the project into an APK with both JavaFXPorts and the new Gluon plugin. However when I try and run my APK on an Android device it always says ‘There was a problem parsing the package’. Is there something I am doing wrong? The project runs fine on the desktop.

I first managed to compile the project with IntelliJ using the Gluon plugin on Ubuntu. However I have now moved to JavaFXPorts with Eclipse on Windows. I managed to get the project compile using the Java 8 SDK but the results are still incompatible with my devices. I am using Gradle to build the project and have been playing around with the buildToolsVersion, targetSdkVersion and compileSdkVersion. But JavaFXPorts requires buildToolsVersion of at least 26.0.2. I have an Android box with a Version string 6.0.1 and have been able to compile and run Android Apps created with the standard Android API v19 but no luck with JavaFX.

Tbh, this more sounds like a "How do I use JavaFX on Android question, and not like a Gradle related question, besides that you use Gradle as build tool. So I suggest you move your question to some community that is better suited for the question.