Whats wrong with my Terrain Set?
I’ve doing it like in the tutorial here:
https://doc.mapeditor.org/en/stable/manual/terrain/
The video tutorial here doesn’t work anymore:
Think now it’s complicated as before (like in die video).
This are the red part above:
result:
Your labels are incorrect. You’ve labelled every tile as being the same - the same red terrain on every edge and every corner. This means those 9 tiles are all the same as far as Tiled is concerned, which is why you’re getting random results.
The red terrain should be only on those corners and edges where the tile has the dark orange artwork (or the light orange, depending on which you want to paint with, but definitely not both).
You’ll need to label all the tiles before Tiled can correctly use them, by the way. Even if you label them correctly, just 9 tiles isn’t enough for this terrain and the tool may still give nonsense results.
You may also want to make a second terrain colour for the other parts, so that those can correctly transition to other tiles that should transition to them (like the pink+yellow terrain tiles on the right in your screenshot). Note, however, if you do this, you’ll no longer be able to paint these terrains onto an empty map since they don’t have transitions to empty anymore, you’ll need to fill the map with some base tiles first.
Did you see the video?
There it is so easy to make a terrain… in real it isn’t it!
I’ve tryed it - no chance in hell. 
I don’t know what exactly i’ve to do. 
Have translated your text… “understand” it… tryed it again (see screenshots).
Do i need a New Corner Set, New Edge Set or a New Mixed Set?
Which tiles need what?
I think I first need to understand what works and how. 
Can i use it with this tileset or not?
It’s all i have!
The video uses corner-based terrains because that’s all Tiled used to support. Your set is Mixed, although you could use a subset of it as a Corner set if you want. If you want to use all the tiles, the type should be Mixed.
You’ve still not finished labelling it (and one of your tiles, the top left one, is still labelled incorrectly). That is why you’re getting incorrect results. You need to label all the relevant tiles.
Also the sides towards the lighter terrain should not be labeled red in this case. It might look a bit ambiguous, but it’s clear given you’d want the two blue edges in the below image to be able to connect:
@eishiya
Thanks.
@bjorn
Thanks, it looks better but it’s not perfect.
The corners are missing and the terrain is assembled “wrong”.
I think with this Tiles i can’t get what i want.
Now it’s a little bit clearer, but i can’t get it to work.
It should look like this example:
Your terrain is still not fully labelled, so of course Tiled doesn’t know which tiles to use in those scenarios where you haven’t labelled the appropriate tiles.
The example Bjorn gave of one tile is just an example of how to label them, you need to label all of them, not just the one example.
Why all? 
I want to use the tiles i’ve labelld and not the others (like pink+yellow).
Sorry if i asking, but this i don’t understand. 
By “all” I mean all the ones pertaining to this terrain, all the orange+yellow tiles.
I think it’s better i do not use terrain, because i don’t need all the other tiles. 
In that case, consider using a corner-based terrain that uses only the 16 tiles that are required for that. That’ll give you all the coverage like in the screenshot you posted, but with all the automation power of terrains. You would be using just a subset of 16 tiles out of the bunch you posted. The 16 tiles I marked with teal dots here are the ones you’d need to use for a corner-based terrain:
OMG, a lot seems to have changed since my last test 1 year ago. 
My results are not getting any better. 
Why i don’t get this little 4 red corners (for selecting the terrain) like in the picture above (from May 21)?
How it looks now I would like to show, but an upload (.png, jpg, .jpeg) is not possible. 
*
Sorry, there was an error uploading that file. Please try again.
The forum lets you just copy+paste images into posts, try that instead of saving them as a file first.
??? 
I want to upload pictures to show my (bad) results. 
Now i did it! 
After a couple of hours of trying…
Now my result is looking like i want to look. 
