recurring error message in logs

2017-05-02 14:54:45,597 http-nio-8443-exec-5874 uri:/secure/AjaxIssueAction!default.jspa username:jagelsd ERROR jagelsd 894x1111381x25 1u9dmz3 /secure/AjaxIssueAction!default.jspa [c.x.j.manager.impl.XporterTemplateManagerImpl] Xporter Template null with id: 16

When I've contacted this user, he told me he has never used XPorter.

I see lot of error messages like this one and the JIRA Server performance are collapsing (may or may not be linked to that)