Europe maps download failed at 80% on 16gb epix 2 version.

Yes

1. With me too. What can I do? 

I connected the watch to the PC and used garmin express to install a part of the Europe map. This is much faster as via wifi and leaves enough memory space for other apps or music. 

How did you do that? When I downloaded the European topographic maps I didn’t see an option to split it?

In garmin express you can choose a region of Europe. You have to connect the watch to a PC.

I did mine via Garmin express I never saw that option 

Me too, never seen this possibility to choose a region!

When you are connected to garmin express and go to manage maps you see all the regions. In the Europe selection you can click on "Change Region". You get a new window to select a region. At the top of that window there is selection bar that list standard: "TopoActive Europe" which is all Europe when you click on this you can choose between: TopoActive Europe - West, East or Central.

It worked for me by removing the Topo Europe map and then reinstalling the new version. I assume it's trying to copy the new file and THEN overwrite the one that's there, so it runs out of space. Removing the one that is there and reinstalling bypasses this mechanism.