I got a notification from Macrium Reflect that an update was available. But when I try to update I get a HTTP Error - 403. This is not really a fix but just For Your Information.
According to information from their forum:
"Appologies, our Content Delivery Network (CDN) cache is behind. Please try again in a few minutes".
So if you use this image backup software and get this error message, just try again later. The problem is on their end and not yours.