Hi cleggink,

Strange, it seems that your project misses a netty class, that is a dependecny of the library, please could you just try to add this to your pom?

<!-- https://mvnrepository.com/artifact/io.netty/netty-all -->
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.46.Final</version>
</dependency>

Regards,
Giuseppe