Can org.apache.httpcomponents.httpclient_4.5.1.jar be replaced with org.apache.httpcomponents.httpclient_4.5.13.jar and the .classpath be modified?

Then you have 3 options.

  1. Just give up performing your test on the remote Jenkins node with your special jar included. Your test works OK on your local PC, doesn’t it? If you can perform your test manually, it’s good enough, isn’t it?
  2. Ask your system administrators so that they help you solve your problem. You only need to read the .log file. Possilbly they can copy the .log file to somewhere for you to read.
  3. Try debugging for yourself; you want to produce a Jenkins environment on a machine for which you have full access (e.g, your local Windows PC), and on it you want try to reproduce your problem. This would be a good lesson for you to understand Jenkins thoroughly.

up to you.