Sönke reimer

I noticed, that version 5.1.4.Final is still JDK 1.6 compatible.
In that version the class SingleIdMapper still has the same code as 4.3.x.

That's right, we didn't migrate to a baseline of JDK 8 until Hibernate 5.2.

Is there a chance for me to build a new fixed hibernate-envers jar based on 4.3.11.Final considering the license ?

Yes, you're more than welcomed to back port changes we make on later releases to earlier releases.