Symptoms

When updating the Universal Plugin Manager, the "Downloading and Installing" dialog never completes.

However, when the user refreshes the page or opens a new tab to Manage Add-ons page, it shows that is was successfully installed.

Cause

This is caused by a bug in UPM 2.16.2. See  Unable to locate Jira server for this macro. It may be due to Application Link configuration.  for more information. 

Workaround

The UPM update has actually succeeded, and refreshing the page will confirm this (either by displaying the new version string in the footer, or by no longer showing the "UPM update available" notification banner). This is a one-time, front-end bug that customers may encounter now, but will not encounter in the future.

Resolution

See workaround. Once version 2.16.2 is installed future updates should not encounter the error.