Is it a bug or a problem displaying my sprites?

Hello, I just noticed a display problem on my character sprites that I created via a vector drawing application and export to png, it's not all the time but it can do it for any character sprite, I have like a thin black line that barely shows but shows, there is a space between the character and the black line but what is bisard is that it does not appear permanently, it is when an enemy character moves or when I move my player, that I see this little black line, I have the impression what is part of the sprite but how could I solve this display problem??? Thank you in advance for your help because I don't see what's causing this black line?

I put you the link of the game so that you see the problem, the black line next to the sprite can also appear sometimes on enemy sprites

dropbox.com/s/igl822jdfiwvkbd/FunShooter%20%2810%29.c3p

Always make sure you have some transparent pixels around your sprites. Sprites are saved to a spritesheet which copies multiple individual sprites to a shared spritesheet. What you are seeing is bleed from another sprite. I can see a black line on the player. If you export your project and look at the spritesheets, you can actually see that sol2 is placed next to your player. It's black border is bleeding into the player when the graphics are scaled to the screen. If you add a pixel all around sol2, the line disappears from player.

Thank you for all this explanation I didn't know all this, how can I add a pixel all around the ground 2???

Edit the image and use Resize Image Canvas. Add two pixels to each dimension and pick Image:Align Center.

Oh yes, thank you, I wasn't thinking about that.

When you export (to Web) you can look inside the final zip file in the images directory. All of the spritesheets are there. It isn't really obvious from just looking at the file that an issue will occur. The best plan is to always give spites a border.

Thank you it can be useful to check a problem