Ultra Run

Press upper right button. Scroll up one to add.  Scroll down and you'll see ultra run as an option to add. Juat press it to add. It will then always show up in your activities list.

Strange thing is, that I did exactly that but cannot see a file called "Ultra Run"

Try looking in the list of activities below your last one  - Press top right, scroll down. You’ll go through your favorites to activities added but not favourites. If not there you’ll get to the ‘+’ again. Press top right again to add then scroll through the list.

If you got the latest update, then it's definitely there somewhere. If you don't see it in the list of activities to "add", then that means you've already added it. So, like philipshambrook said, check your Favorites list (press the top-right button), and if it's not there then keep scrolling down to below your favorites and see if it's there.

maybe someone can publish the ultra run fit file from the SPORTS folder here?

Press Start to get to the list of your activities

1) The list in white is your favourites list.  If not there keep scrolling down

2) The list then turns black, they're installed activities but not favourites. If not there, scroll down to the green +/ADD and press START

3)This list is now all the installed activities your watch can do - scroll down this list to the bottom it should be there

Do you already have the update with the ultra run? If so, could you provide the fit file?

I installed the Release Candidate manually

ok, if you or someone already has the ultra run fit file, it would be nice if someone could provide it.

I doubt it would work on any other version of the s/w