Pattern created in Illustrator shows hairline edge when placed as smart object in photoshop

[Emily6892]

I have created a pattern in Illustrator, but when I am in photoshop trying to make a mockup of that pattern as wallpaper, it shows a hairline edge at the same spot as the tile edge in Illustrator's pattern editor.  In photoshop, I used 'file>place linked' to place the smart object. In illustrator, the smart object file doesn't show any hairline edges, so I'm not sure why they show in Photoshop.  Any ideas?

[Ton Frederiks]

What is the resolution of the Photoshop file?

You may try to resample it to a multiple of 72 ppi, so if the file is 300 ppi, try 288 ppi.