How to fix this weird black lines on mesh?

Hello guys. I made path for my game (almost biggest size possible part). But when I added surface appearance to it, I got weird result:
image
You can see here black lines near road. Is there any way to remove them?
Path texture:

Greetings! There are two really simple fixes that might work in this case.

First, go to edit mode in Blender, then mesh in the top left corner. At the bottom of the category is “Clean up”, hover over that, then click “Delete loose”.

Another possible fix if that doesn’t work is simply recalculating the normals.
(Edit mode > Mesh > Normals > Recalculate Outside)

These are two possible ways to fix it, otherwise, it’s going to be another problem.

Hope this helps!

Sadly, none of this 2 ways helped me. Do you know any other possible issues with texture?
Also, in blender everything looks good, only studio is bad.

try smoothing or auto smoothing in blender (almost same thing) i have NO idea if it’ll work but doesn’t hurt to try i guess