Symptoms

Universal Plugin Manager is unable to install new add-ons or update existing add-ons.

The following error message is displayed: "Invalid anti-XSRF token provided. The valid token should be retrieved transparently, but you may want to perform a hard refresh in your browser and try again before creating a support issue"

Diagnosis

JIRA is being accessed through a proxy server.

Cause

The proxy server appears to be introduce this error, but exact cause of this issue is currently unknown.

Workaround

Method 1:

Install plugin manually by file upload: Installing add-ons by file upload

Method 2:

Bypass the proxy server and access JIRA directly to install plugins via the UPM.