Windows10, NVivo 12 Plus (version 12.5.0.815 64-bit).

I open NVivo and it says that an update for 12.6 has been downloaded and is waiting for installation.

I select Install Now, and it goes through a process to try and install.

This then opens a cmd window. Over the cmd window, a loading box displays and closes.

Then closes the cmd window.

Then a Preparing to install window opens. the progress bar progresses.

It closes, but nothing happens.

When I open a NVivo project, it (again) asks if i want to upgrade to the new version 12.6.

I have tried this by launching NVivo as both a standard user and as an admin user, neither works.

i have also tried this with NVivo not running, and with NVivo running. This doesn't change the outcome.

I have restarted my computer and still this does not work.

I want the upgrade.

I do not want to uninstall NVivo, so won't upgrade if this is required.