Why do I get a signature signing error when calling the "orElseThrow ()" method

Question

Why am I getting the following exception?

Called: java.lang.reflect.GenericSignatureFormatError: Signature parsing error: Expected field type signature. Remaining input: + Ljava / lang / AssertionError;

when using the orElseThrow method for an Optional result:

 public void removeFP(String port, String flight) { FPDto fp = findFP(port, flight).orElseThrow(() -> new AssertionError("...")); flightplans.remove(fp); } 

I am deploying Glassfish v 4.1 on the JDK 8_u25. Eclipse Kepler SR2 with Java 8 support does not show any syntax errors.