I ran into error when I tried to do full backup of ArcGIS Enterprise 10.5.1 by using Webgisdr tool.  Anyone know how to resolve the issue?

c:\Program Files\ArcGIS\Portal\tools\webgisdr>webgisdr --export --file c:\xxxxxx\Testwebgisdr.properties

C:\Program Files\ArcGIS\Portal\tools\webgisdr\webgisdr.log.lck

==========================================

Starting the webgisdr utility.

==========================================

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/co

dec/binary/Base64

       at org.apache.http.impl.auth.GGSSchemeBase.<init>(GGSSchemeBase.java:79)

       at org.apache.http.impl.auth.SPNegoScheme.<init>(SPNegoScheme.java:51)

       at org.apache.http.impl.auth.SPNegoSchemeFactory.create(SPNegoSchemeFact

ory.java:66)

       at org.apache.http.impl.client.AuthenticationStrategyImpl.select(Authent

icationStrategyImpl.java:175)

       at org.apache.http.impl.client.TargetAuthenticationStrategy.select(Targe

tAuthenticationStrategy.java:43)

       at org.apache.http.impl.auth.HttpAuthenticator.handleAuthChallenge(HttpA

uthenticator.java:154)

       at org.apache.http.impl.execchain.MainClientExec.needAuthentication(Main

ClientExec.java:557)

       at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.

java:275)

       at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java

:195)

       at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:86)

       at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java

:108)

       at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttp

Client.java:184)

      at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttp

Client.java:82)

       at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttp

Client.java:106)

       at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttp

Client.java:57)

       at com.esri.arcgis.webgis.util.HttpUtil.b(HttpUtil.java:423)

       at com.esri.arcgis.webgis.util.HttpUtil.isURLAvailable(HttpUtil.java:340

)

       at com.esri.arcgis.webgis.util.ValidationUtil.isComponentReachable(Valid

ationUtil.java:547)

       at com.esri.arcgis.webgis.service.impl.WebGISDRFrontController.service(W

ebGISDRFrontController.java:66)

       at com.esri.arcgis.webgis.service.impl.WebGISDRManager.b(WebGISDRManager

.java:117)

       at com.esri.arcgis.webgis.service.impl.WebGISDRManager.exportWebGIS(WebG

ISDRManager.java:101)

       at com.esri.arcgis.webgis.client.WebGISDR.main(WebGISDR.java:99)

Caused by: java.lang.ClassNotFoundException: org.apache.commons.codec.binary.Bas

e64

       at java.net.URLClassLoader.findClass(URLClassLoader.java:381)

       at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

       at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)

       at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

       ... 22 more