I am trying to set up the JIRA plugin so that after a Jenkins build a comment is added to the corresponding issues in JIRA.

I installed the JIRA plugin and added the update relevant JIRA issues build step (see jeninsprojectconfig attachment). And I've enabled the remote API for jira (see atlassiansetup)

When I try to enter my JIRA credentials in the JIRA sites settings within Jenkins, it always give me a (404) Not Found error when I try to validate the settings. (See jenkingsconfig attachment).

If I ignore that and push a build with Jenkins, the build is successful, but at the end of the build it says the following: "Error updating JIRA issues. Saving issues for next build." And the comment is never added to JIRA.

Any thoughts?