I am facing java.lang.NullPointerException exception while coping artifact through SCP task

[Suvankar Dey]

Starting task 'Copy Artifact to NP2 QAPROD' of type 'com.atlassian.bamboo.plugins.bamboo-scp-plugin:scptask'
simple	19-Mar-2018 03:33:10	Connecting to dkdl6351.dcsgomni.com on port: 22
error	19-Mar-2018 03:33:10	Error occurred while running Task 'Copy Artifact to NP2 QAPROD(3)' of type com.atlassian.bamboo.plugins.bamboo-scp-plugin:scptask.
error	19-Mar-2018 03:33:10	java.lang.NullPointerException
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.plugins.scp.SSHKeyProvider.<init>(SSHKeyProvider.java:26)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.plugins.scp.ScpTask.execute(ScpTask.java:257)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.plugins.scp.ScpTask.run(ScpTask.java:120)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.plugins.scp.ScpTask.execute(ScpTask.java:106)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.task.TaskExecutorImpl.lambda$executeTasks$1(TaskExecutorImpl.java:281)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.task.TaskExecutorImpl.executeTaskWithPrePostActions(TaskExecutorImpl.java:224)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.task.TaskExecutorImpl.executeTasks(TaskExecutorImpl.java:281)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.task.TaskExecutorImpl.execute(TaskExecutorImpl.java:112)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.build.pipeline.tasks.ExecuteBuildTask.call(ExecuteBuildTask.java:71)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent.executeBuildPhase(DefaultBuildAgent.java:203)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent.build(DefaultBuildAgent.java:175)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.v2.build.agent.BuildAgentControllerImpl.lambda$waitAndPerformBuild$0(BuildAgentControllerImpl.java:122)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.variable.CustomVariableContextImpl.withVariableSubstitutor(CustomVariableContextImpl.java:185)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.v2.build.agent.BuildAgentControllerImpl.waitAndPerformBuild(BuildAgentControllerImpl.java:117)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent$1.run(DefaultBuildAgent.java:126)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.utils.BambooRunnables$1.run(BambooRunnables.java:48)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.security.ImpersonationHelper.runWith(ImpersonationHelper.java:26)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.security.ImpersonationHelper.runWithSystemAuthority(ImpersonationHelper.java:17)
error	19-Mar-2018 03:33:10		at com.atlassian.bamboo.security.ImpersonationHelper$1.run(ImpersonationHelper.java:41)
error	19-Mar-2018 03:33:10		at java.lang.Thread.run(Thread.java:748)
simple	19-Mar-2018 03:33:10	Finalising the build...
simple	19-Mar-2018 03:33:10	Stopping timer.

[Alexey Chystoprudov]

It looks like https://jira.atlassian.com/browse/BAM-19712, which is fixed in next minor release planned for this week

[Suvankar Dey]

Thanks everyone . I got the solution, there was some problem with private keys. Now its fine 

[Charlie Misonne]

Did your plan move to another project recently? Or was it cloned from another one?

I encountered this behavior in the past. The solution was to delete every task related to the artifacts (artifact definition, artifact download, scp task) and recreate them.

See this bug report as well https://jira.atlassian.com/browse/BAM-15033

[Suvankar Dey]

No, Plan is not moved to another project and there is no clone. Manually i have created this. 
Problem is that whenever I am selecting "Use SSH custom key" option under Authentication type, its asking to browse and upload keys without any uncheck option.