Weird crosshatch effect after export

I am probably too late.. But I faced the same issues with some pictures. I see the checked pattern disappear after i turned off the grain. 

Great catch Todd. If this is the issue, another approach could be to turn off the lens correction but this image definitely needs a bit of luminance smoothing

gregt98010239  wrote Everyone says its probably because my iso was to high or just to set my grain, sharpen, and noise reduction to 0 to fix the problem. It works but this was never a problem before. I used to shoot at a very high iso and use all the tools i stated above for years. This just started happening a couple months ago and i still cant find a solution.

Did you perhaps buy a new lens and its happening when shooting with this lens? See the below post with a similar issue due to the Lens Profile causing a moire' pattern in high ISO shots.

Lightroom 4: Moire when Sharpening and Profile Correction used together | Photoshop Family Customer Community

Here's what Adobe Engineer Eric Chan said at the above post

What you are seeing here is image noise that is (1) becoming patterned due to the radially-symmetric warp used by the distortion correction, and (2) amplified by the sharpening. My suggestion is to (a) use more luminance noise reduction, and (b) use more Masking with the sharpening to avoid amplifying the noise.

The crosshatch moire' pattern in the OP's 4301B0234.jpg image file is due to the combination of Lens Profile AND Rotation corrections. Here's why:

This ISO 3200 image is very noisy, has a high 73 Sharpening setting, and 0 Luminace setting.

SOLUTION

Adjust the Sharpening and Luminance Noise Reduction controls at 1:1 Zoom view to reduce visible noise. A setting in the 25 to 50 range should "fix" the issue.

It exists. Take the 4301B0234.jpg at 1:1  exposure, -.36, contrast 100 - I think you'll see it.

The Grid pattern is not visible on my system. Neither in LR or the Win 7 Photo Viewer program.

So it is something on your system and not in the image itself.

This is very hunchy, but I believe I've seen effects such as this when exporting "extremely" processed files at certain pixel-widths. The result is, in effect, a rectilinear moire, and the solution iirc was to choose an export width that was a multiple of some of the common denominators of the original image; eg for a 2400 pixel width, I might go with 1200, or 1600, 800, or 600.

After writing above, I took a look at your two images in LR. Saw the output was tilted, experimented to see that tilting the original 1.19 seems to be a perfect match, and also matches your output's dimensions. Rules out my first theory, now I wonder if the tilt has something to do with the moire.  I did what I could to stress it ( output at zero quality, too) - but I couldn't get your checkerboard result.

1) Perhaps dropboxing the original raw, xmp, and your export settings - and we could see if we can replicate.

2) Is there some other 'gotcha' that might be involved. Is the output image you provided the actual image as opposed to a screenshot? Any other differences between how you handled this shot versus ones in the past? There's no way you could be printing a Smart Preview?

And you see this IN Develop when viewing at 1:1?

Or you see it in the exported image at 1:1 (100% zoom)?