We are receiving below exception while we are sftp . Could you please do the needful. Looks like this execption is 

188: com.jcraft.jsch.JSchException: Algorithm negotiation fail

        at org.apache.tools.ant.taskdefs.optional.ssh.Scp.execute(Scp.java:245)

        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)

        at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

        at java.lang.reflect.Method.invoke(Method.java:601)

        at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)

        at org.apache.tools.ant.Task.perform(Task.java:348)

        at org.apache.tools.ant.Target.execute(Target.java:390)

        at org.apache.tools.ant.Target.performTasks(Target.java:411)

        at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)

        at org.apache.tools.ant.Project.executeTarget(Project.java:1368)

        at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)

        at org.apache.tools.ant.Project.executeTargets(Project.java:1251)

        at org.apache.tools.ant.Main.runBuild(Main.java:809)

       at org.apache.tools.ant.Main.startAnt(Main.java:217)

        at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)

        at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)

Caused by: com.jcraft.jsch.JSchException: Algorithm negotiation fail

        at com.jcraft.jsch.Session.receive_kexinit(Session.java:552)

        at com.jcraft.jsch.Session.connect(Session.java:299)

        at com.jcraft.jsch.Session.connect(Session.java:162)

        at org.apache.tools.ant.taskdefs.optional.ssh.SSHBase.openSession(SSHBase.java:223)

        at org.apache.tools.ant.taskdefs.optional.ssh.Scp.upload(Scp.java:299)

        at org.apache.tools.ant.taskdefs.optional.ssh.Scp.execute(Scp.java:224)

        ... 16 more