Look at texture, wtf?
What program are you using to create your splat maps? From the filename it looks like World Machine - if it is, you may have to play with the Edge Blending - also make sure that the option “Calculate edge tiles on partial tilesets” is set. Check out http://forum.world-machine.com/index.php?topic=2400.0
Have you zoomed in from the World Composition window in UE and made sure it is aligned perfectly?
Yes, aligned good
No, not 1010, i create one splatmap for all world, and problem fixed, thx for all )
I’m afraid I’m out of ideas, my guess is the stretched texture (1009) is antialiasing the edges - perhaps you could make it 1010 so it overlaps?