My water is invisebil, I need Help

Hello I need Help with my Water system,
when I try to place a river down the Material is invisebil. And I cant find a solution. (excuse my bad english, Im from Germany)

Are you using the UE water plugin?
Do you have a landscape in your level?
Is “Enable Edit Layers” checked on that landscape?
Are all of the river’s spline points within the landscape bounds?

If you can answer all of these with “Yes”, then we need screenshots of the viewport and the details panel for the relevant actors.

Also, quick tip: Try to avoid backticks (`) where apostrophes (’) belong or you’ll mess up your formatting, as you can see in your post.

Sry btw for my late answer