The issue is in the "radius.jar". This can't be fixed in the module's code or your code. It's an issue with that old library. And the reason it is crashing is because Google made a breaking-change in Android 8.0 where you're no longer allowed to start a service while the app is in the background... unless you make it a "foreground" service. But you can only make it a "foreground" service via a code change because it involves displaying a notification in the top status bar.
I am using https://github.com/jamesfalkner/liferay-android-beacons
It's using a "radius.jar" which is documented as a 2014 release. This jar library contains the "com.radiusnetwork.ibeacon" classes which is causing this exception. https://github.com/jamesfalkner/liferay-android-beacons/tree/master/lib
The issue is in the "radius.jar". This can't be fixed in the module's code or your code. It's an issue with that old library. And the reason it is crashing is because Google made a breaking-change in Android 8.0 where you're no longer allowed to start a service while the app is in the background... unless you make it a "foreground" service. But you can only make it a "foreground" service via a code change because it involves displaying a notification in the top status bar.