updated Jenkins server but kept Jenkins $HOME from old server. Updated installed plugins including S3 plugin, S3 plugin started throwing errors:
java.lang.NoClassDefFoundError: org/apache/http/conn/scheme/SchemeSocketFactory
java.lang.NoClassDefFoundError: org/apache/http/protocol/HttpContext
I had to drop the httpclient-4.4 and httpcore-4.4 jars from another plugin into the S3 plugin to make it work
We're getting this same issue. I've tried the solution posted above, but either I don't know enough about Java (likely), or it isn't working on our setup. I got the jar files from here: http://apache.mesi.com.ar/httpcomponents/httpclient/binary/httpcomponents-client-4.4-bin.tar.gz