NPE is thrown when execute source command from client/ssh

2017-08-30T14:48:25,935 | ERROR | Thread-133       | he.karaf.shell.support.ShellUtil  149 | 107 - org.apache.karaf.shell.core - 4.1.2 | Exception caught while executing command
java.lang.NullPointerException: null
	at org.apache.karaf.shell.commands.impl.SourceAction.execute(SourceAction.java:71) [105:org.apache.karaf.shell.commands:4.1.2]
	at org.apache.karaf.shell.impl.action.command.ActionCommand.execute(ActionCommand.java:84) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:68) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:86) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:571) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:497) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:386) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.felix.gogo.runtime.Pipe.doCall(Pipe.java:417) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.felix.gogo.runtime.Pipe.call(Pipe.java:229) [107:org.apache.karaf.shell.core:4.1.2]
	at org.apache.felix.gogo.runtime.Pipe.call(Pipe.java:59) [107:org.apache.karaf.shell.core:4.1.2]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:?]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:?]
	at java.lang.Thread.run(Thread.java:745) [?:?]

session.currentDir(null);