Exception encountered when attempting to run a suite with class name: scalafx.event.SubscriptionEventHandler *** ABORTED ***
   java.lang.VerifyError: Bad type on operand stack
 Exception Details:
   Location:
     scalafx/beans/binding/StringExpression.$less(Lscala/runtime/Null$;)Ljavafx/beans/binding/BooleanBinding; @5: invokevirtual
   Reason:
     Type 'scala/runtime/Null$' (current frame, stack[1]) is not assignable to 'java/lang/String'
   Current Frame:
     bci: @5
     flags: { }
     locals: { 'scalafx/beans/binding/StringExpression', 'scala/runtime/Null$' }
     stack: { 'javafx/beans/binding/StringExpression', 'scala/runtime/Null$' }
   Bytecode:
     0000000: 2ab6 001d 2bb6 0047 b0
   at scalafx.beans.property.StringProperty$.apply(StringProperty.scala:41)
   at scalafx.event.SubscriptionEventHandler$$anonfun$1.apply$mcV$sp(SubscriptionEventHandler.scala:38)
   at scalafx.event.SubscriptionEventHandler$$anonfun$1.apply(SubscriptionEventHandler.scala:37)
   at scalafx.event.SubscriptionEventHandler$$anonfun$1.apply(SubscriptionEventHandler.scala:37)
   at org.scalatest.Transformer$$anonfun$apply$1.apply(Transformer.scala:22)
   at org.scalatest.Transformer$$anonfun$apply$1.apply(Transformer.scala:22)
   at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
   at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
   at org.scalatest.Transformer.apply(Transformer.scala:22)
   at org.scalatest.Transformer.apply(Transformer.scala:20)
   ...