Change reference_gauge paremeter to Long Change the reference_gauge paremeter of the GaugeDischargeCurveArtifact from Double to Long. It doesn't change the behaviour but the reference is a long value in the database too.

<?xml version="1.0" encoding="UTF-8" ?>
<datacage>
    <user>SA</user>
    <password/>
    <driver>org.h2.Driver</driver>
    <url>jdbc:h2:${artifacts.config.dir}/../h2/datacage</url>
</datacage>