There are two types of wrapper exceptions commonly used in Maven plugins, the MojoFailureException and MojoExecutionException. It's not obvious which one is the correct one to use, so here is a simple explanation. A MojoExecutionException typically means that an unexpected and unrecoverable error happened while running the plugin. This would be something like a NullPointerException or other RuntimeException that the plugin developer did not expect and/or can not handle. It's basically a plugin crash.
A MojoFailureException means that there was a problem in the build which the plugin detected, and the plugin is now notifying you of that failure. This would be something like a Java source file that couldn't compile. The build can not continue, but the plugin is still working normally.
More information can be found in the Sonatype Maven book.