SFTP does not work

I create a flow service that invokes pub.client:sftp.login. I supplied userAlias for SFTP configured.

It throws an error running:
com.wm.app.b2b.server.ServiceException: com.jcraft.jsch.JSchException: failed to send channel request
com.jcraft.jsch.JSchException: failed to send channel request
at pub.CommonUtils.throwAsServiceException(CommonUtils.java:82)
at pub.client.sftp.login(sftp.java:418)
at sun.reflect.GeneratedMethodAccessor179.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.wm.app.b2b.server.JavaService.baseInvoke(JavaService.java:404)
at com.wm.app.b2b.server.invoke.InvokeManager.process(InvokeManager.java:646)
at com.wm.app.b2b.server.util.tspace.ReservationProcessor.process(ReservationProcessor.java:39)
at com.wm.app.b2b.server.invoke.StatisticsProcessor.process(StatisticsProcessor.java:49)
at com.wm.app.b2b.server.invoke.ServiceCompletionImpl.process(ServiceCompletionImpl.java:243)
at com.wm.app.b2b.server.invoke.ValidateProcessor.process(ValidateProcessor.java:49)
at com.wm.app.b2b.server.invoke.PipelineProcessor.process(PipelineProcessor.java:171)
at com.wm.app.b2b.server.ACLManager.process(ACLManager.java:299)
at com.wm.app.b2b.server.invoke.DispatchProcessor.process(DispatchProcessor.java:34)
at com.wm.app.b2b.server.AuditLogManager.process(AuditLogManager.java:377)
at com.wm.app.b2b.server.invoke.InvokeManager.invoke(InvokeManager.java:545)
at com.wm.app.b2b.server.invoke.InvokeManager.invoke(InvokeManager.java:382)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:234)
at com.wm.app.b2b.server.BaseService.invoke(BaseService.java:215)
at com.wm.lang.flow.FlowInvoke.invoke(FlowInvoke.java:257)
at com.wm.lang.flow.FlowState.invokeNode(FlowState.java:520)
at com.wm.lang.flow.FlowState.step(FlowState.java:389)
at com.wm.lang.flow.FlowState.invoke(FlowState.java:360)
at com.wm.app.b2b.server.FlowSvcImpl.baseInvoke(FlowSvcImpl.java:1124)
at com.wm.app.b2b.server.invoke.InvokeManager.process(InvokeManager.java:646)
at com.wm.app.b2b.server.util.tspace.ReservationProcessor.process(ReservationProcessor.java:39)
at com.wm.app.b2b.server.invoke.StatisticsProcessor.process(StatisticsProcessor.java:49)
at com.wm.app.b2b.server.invoke.ServiceCompletionImpl.process(ServiceCompletionImpl.java:243)
at com.wm.app.b2b.server.invoke.ValidateProcessor.process(ValidateProcessor.java:49)
at com.wm.app.b2b.server.invoke.PipelineProcessor.process(PipelineProcessor.java:171)
at com.wm.app.b2b.server.ACLManager.process(ACLManager.java:299)
at com.wm.app.b2b.server.invoke.DispatchProcessor.process(DispatchProcessor.java:34)
at com.wm.app.b2b.server.AuditLogManager.process(AuditLogManager.java:377)
at com.wm.app.b2b.server.invoke.InvokeManager.invoke(InvokeManager.java:545)
at com.wm.app.b2b.server.invoke.InvokeManager.invoke(InvokeManager.java:382)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:234)
at com.wm.app.b2b.server.comm.DefaultServerRequestHandler.handleMessage(DefaultServerRequestHandler.java:119)
at com.wm.app.b2b.server.HTTPMessageHandler.process(HTTPMessageHandler.java:156)
at com.wm.app.b2b.server.HTTPDispatch.handleRequest(HTTPDispatch.java:170)
at com.wm.app.b2b.server.Dispatch.run(Dispatch.java:385)
at com.wm.util.pool.PooledThread.run(PooledThread.java:127)
at java.lang.Thread.run(Thread.java:748)
Caused by: com.jcraft.jsch.JSchException: failed to send channel request
at com.jcraft.jsch.Request.write(Request.java:65)
at com.jcraft.jsch.RequestSftp.request(RequestSftp.java:47)
at com.jcraft.jsch.ChannelSftp.start(ChannelSftp.java:237)
at com.jcraft.jsch.Channel.connect(Channel.java:152)
at com.jcraft.jsch.Channel.connect(Channel.java:145)
at com.wm.app.b2b.server.sftp.client.SFTPSession.(SFTPSession.java:20)
at com.wm.app.b2b.server.sftp.client.SFTPSession.createSession(SFTPSession.java:28)
at com.wm.app.b2b.server.sftp.client.SFTPSessionManager.addSession(SFTPSessionManager.java:75)
at pub.client.sftp.login(sftp.java:411)
… 40 more

The connection is tested and works fine.
Can someone help me with this one?

Hi Chandra,

which version of wM are you running on?

Are there any Fixes applied to this installation?
Check for IS_Core as well as SCG-TPS and SCG-TPL fixes if they contain updates to the SFTP feature.
There has been an update for the JCraft SecureChannel lib which is used in this context.

Regards,
Holger