AR Android app crashes as soon as a serialized library is linked to the AR Tracked Image Manager

I am building an Ar Android app using Unity 2021.3.9f1 and AR Foundation. Everything works perfectly until the ReferenceImageLibrary is assigned to the AR Tracked Image Manager. As soon as that happens the built Android app crashes right at startup. If the field (Serialized Library) is left empty, the app works normally but of course without image tracking. What else I tried: - different images (transparent and not transparent) - create the Tracked Image Manager and the ReferenceImageLibrary at runtime -> causes a crash I also don't know of any method to find out the cause of the crash on an Android device. Thanks in advance for your help!