problems with tiles, when run in viewer you can see white line between 2 tiles

GLGAMES

I am making a new project with lots of tiles, but once you run it in viewer or test on device you can see a white line in between 2 tiles.
But it only appears in the middle of the screen. the rest of the tiles seems to be unaffected.
Here is a screenshot.

Benjamin_m5

Wow, look very nice

I had this problem with a game too. What i made was:

If i had an actor sized 38 x 38 i made an image with the size 40 x 40 with one line arond only transparent pixles. After i hadn't white or black lines on my retina display
Hope that helps
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Benjamin

GLGAMES

but this problem only shows up in the middle of screen no where else, that's what i find strange.