Inconsistency between display-dependency-updates and dependency-updates-report

[itroll42]

I'm trying to run the dependency-updates-report on a multi module project.

I'm running this plugin on the parent pom of an application that contains 11 modules total.

The plugin fails with Execution default-cli of goal org.codehaus.mojo:versions-maven-plugin:2.16.2:dependency-updates-report failed: Cannot invoke "String.startsWith(String)" because the return value of "org.apache.maven.model.Dependency.getVersion()" is null -> [Help 1]

I've verified that all versions between the different sub poms and parent are good. In that theres no drift according to the documentation here: https://www.mojohaus.org/versions/versions-maven-plugin/examples/resolve-ranges.html

What I have seen however is that the display-dependency-updates works. And does spit out a listing of all libraries for each sub module independently.

Is the report not designed to do the same thing? Or what may I be doing wrong thats causing the report to fail, but the other way works?