Please provide more info about Jenkins/plugin versions you use and the error you see in logs

https://wiki.jenkins.io/display/JENKINS/How+to+report+an+issue

Facing this in post build

 
20:01:45 Build step 'Invoke Gradle script' changed build result to FAILURE*20:01:45* Build step 'Invoke Gradle script' marked build as failure*20:01:48* ERROR: Build step failed with exception*20:01:48* java.lang.NullPointerException*20:01:48* at hudson.plugins.jira.JiraSession.createIssue(JiraSession.java:416)20:01:48 at hudson.plugins.jira.JiraCreateIssueNotifier.createJiraIssue(JiraCreateIssueNotifier.java:200)20:01:48 at hudson.plugins.jira.JiraCreateIssueNotifier.currentBuildResultFailure(JiraCreateIssueNotifier.java:356)20:01:48 at hudson.plugins.jira.JiraCreateIssueNotifier.perform(JiraCreateIssueNotifier.java:155)20:01:48 at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:45)20:01:48 at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:744)20:01:48 at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:690)20:01:48 at hudson.model.Build$BuildExecution.post2(Build.java:186)20:01:48 at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:635)20:01:48 at hudson.model.Run.execute(Run.java:1840)20:01:48 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)20:01:48 at hudson.model.ResourceController.execute(ResourceController.java:97)20:01:48 at hudson.model.Executor.run(Executor.java:429)20:01:48 Build step 'JIRA: Create issue' marked build as failure*20:01:48* Finished: FAILURE

Not enough information to investigate further, no response to comment asking for information.