Could not connect to Salesforce.com after upgrading to JIRA plugin v3.0+

This is usually caused by the wrong Server URL in the JIRA configuration screen for Salesforce. The plugin version 3.0 and above uses version 14.0 of the Salesforce WSDL and this needs to be reflected in the URL. Please see the first chapter in the installation guide (“Installing the plugin”) for details. Several clients have had this same error when they upgraded their plugin but not the URL.