commons-lang was available in spigot previously but is no longer included, so this now results in a NoClassDefFoundError. Please switch to lang3 and declare it as a dependency:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

I guess this still is a valid issue to be fixed in the next release, to not use a commons exception for that.

nevermind, this is my fault for not having a specific enough relocation policy when shading