There is a small bug in the hudson Version Number Plugin that causes the build of a job to fail if there are no existing (previous) builds and if the option "Don't increment builds today/ this month/ this year/ all time after a failed build" is activated. The cause is that the Version Number Plugin doesn't create a version number but throws a NullPointerException (visible in the Build Log).

I looked at the source code of the plugin and discovered the problem:
The source of the NullPointerException seems to be the call to prevBuild.getResult() if skipFailedBuilds == true and before the check if (prevBuild != null) is performed.

I have attached a Subversion patch file that should correct this issue.

(Couldn't select component versionnumber for this issue because it doesn't exist)