FATAL: Null value not allowed as an environment variable: GIT_COMMIT
java.lang.IllegalArgumentException: Null value not allowed as an environment variable: GIT_COMMIT
at hudson.EnvVars.put(EnvVars.java:356)
at hudson.EnvVars.put(EnvVars.java:74)
at hudson.plugins.git.GitSCM.buildEnvVars(GitSCM.java:983)
at hudson.model.AbstractBuild.getEnvironment(AbstractBuild.java:919)
at hudson.plugins.git.GitSCM.checkout(GitSCM.java:865)
at hudson.model.AbstractProject.checkout(AbstractProject.java:1414)
at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:652)
at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:88)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:561)
at hudson.model.Run.execute(Run.java:1678)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:231)

The jobs works if it's modified to normal and build with "Build now".
We encountered the same behaviour with Git plugin 2.0 and not parameterized builds.