Map update failing

I receive the following error during the advertised map update via Garmin Express - "There was an error installing the update"

The error appears after the message "Activating maps" displays briefly on Garmin Express during the installation process. The download appears to complete successfully.

Running V3.3 on the Forerunner945 - trying to update to TopoActive Africa V6.0 using Garmin Express V6.19.3.0

Have also followed others advice on ensuring space is available on the watch \ attempted hard reset of watch \ reinstalling Garmin Express \ rebooted PC.

Nothing appears to resolve the problem.

Looking forward to a solution from Garmin\anyone else.