I updated my jenkins to latest (2.184) and installed the artifactory plugin to try out the upload of built binaries from a fresh project.

Getting these errors in my job console log: 
Jenkins Artifactory Plugin version: 3.3.2*09:52:17* No Artifactory server configured for null. Please check your configuration.09:52:17 FATAL: No Artifactory server configured for null. Please check your configuration.09:52:17 java.io.IOException: No Artifactory server configured for null. Please check your configuration.09:52:17 at org.jfrog.hudson.util.RepositoriesUtils.validateServerConfig(RepositoriesUtils.java:191)09:52:17 at org.jfrog.hudson.generic.ArtifactoryGenericConfigurator.setUp(ArtifactoryGenericConfigurator.java:291)09:52:17 at hudson.model.Build$BuildExecution.doRun(Build.java:157)09:52:17 at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:504)09:52:17 at hudson.model.Run.execute(Run.java:1818)09:52:17 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)09:52:17 at hudson.model.ResourceController.execute(ResourceController.java:97)09:52:17 at hudson.model.Executor.run(Executor.java:429)

Job config lists multiple selections even though I configured only one server.
Please see attached image for details.

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This is what I've configured/investigated to help your debugging:

A) Artifactory server is configured properly in Jenkins->Configuration (as seen in the attached image). Ensured that "Test connection" it returns a valid value: "Found Artifactory 6.10.2
"
B) Using a simple Generic-Artifactory Integration selection with file spec.

C) Repo list through curl on server is fine:
Curl (curl -u<user> https://..../artifactory/api/repositories?type=local) returns valid repo list.

D) A different older instance of jenkins with version 2.164.1 shows a different UI in config (see attached image - old-working-config.jpg) and is working fine.

E) The config on current jenkins server worked fine a few days back and uploaded my files successfully. Problems started since jenkins upgrade and reinstall of plugin. I downgraded the war and plugin and checked but still didn't help.

F) Did a search for any existing problems but didn't find. This error has been reported earlier but seems to be an old closed issue, possibly occurring again.