dslGenerateXML gives Error: Could not find or load main class property(java.lang.String, undefined)

[vtshadow]

When running de dslGererateXml task i get following Error: Could not find or load main class property(java.lang.String, undefined)

I made a new gradle project and used the build.gradle from https://github.com/heremaps/gradle-jenkins-jobdsl-plugin/blob/master/example/build.gradle

the jobdsl is on the default location src/jobdsl.

I use Intellij 2020.3.2
gradle 6.5.1

do you know why the error pops up ?

[vtshadow]

looks like something goes wrong when upgrading gradle