When I run the below command it can successfully work at the first times. 

java -jar /opt/jenkins/jenkins-cli.jar -http -auth admin:xxxxxx -logger FINE -s http://localhost:8080 help

But, after running the command several times, the output changes, and I start getting the following error message : 

Jun 25, 2019 5:37:39 AM hudson.cli.CLI _main
FINE: using connection mode HTTP
Jun 25, 2019 5:37:39 AM hudson.cli.CLI plainHttpConnection
FINE: Trying to connect to http://localhost:8080/ via plain protocol over HTTP
Jun 25, 2019 5:37:39 AM hudson.cli.FullDuplexHttpStream tryToResolveRedirects
FINE: Failed to resolve potential redirects
_java.io.IOException: Server returned HTTP response code: 500 for URL: http://localhost:8080/_
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1894)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1492)
at hudson.cli.FullDuplexHttpStream.tryToResolveRedirects(FullDuplexHttpStream.java:102)
at hudson.cli.FullDuplexHttpStream.<init>(FullDuplexHttpStream.java:55)
at hudson.cli.CLI.plainHttpConnection(CLI.java:279)
at hudson.cli.CLI._main(CLI.java:271)
at hudson.cli.CLI.main(CLI.java:83)

Jun 25, 2019 5:37:39 AM hudson.cli.FullDuplexHttpStream <init>
FINE: establishing download side
_java.io.IOException: Server returned HTTP response code: 500 for URL: http://localhost:8080/cli?remoting=false_
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1894)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1492)
at hudson.cli.FullDuplexHttpStream.<init>(FullDuplexHttpStream.java:72)
at hudson.cli.CLI.plainHttpConnection(CLI.java:279)
at hudson.cli.CLI._main(CLI.java:271)
at hudson.cli.CLI.main(CLI.java:83)