So I bought warframe on my PC. I played it on my Nintendo Switch before. When I start the game I enter the warframe acc data for my Nintendo Switch acc so that I keep all the old things in-game. If I then go on, the mission comes with first. If I then choose my warframe, I'm simply thrown out of the game. Why is that?!
It is unknown.
It may help to change DX mode in the launcher.
A repair of the game could also be worthwhile.
What do you mean by DX mode?
You should be able to select the DirectX feature set that is used. So between DX10 or 11 it was still possible to choose a few version numbers.