1 -2 GB photoshop files? That's very close to the absolute maximum size of a psd file of 2GB. You're sharpening and reducing noise on top of the photoshop psd? You really should do that in the capture phase in the raw not after it has gone through photoshop. It should still just work however but perhaps this is where the issue lies and why nobody else has this issue. What kind of photoshop files are these? Do they (as they should) have maximum compatibiity turned on in Photoshop? Does the same thing happen if you use tiff from photoshop? Are they 1 GB because they are stitched panos or because they have many many layers? What dimensions are these if they are panos? Be aware that there is a maximum size for images processed in camera raw/Lightroom of 65,000 pixels on the long side and 512 MP maximum total. practically that means for 360x180 panos (I now see in your screen shot that that's what you're doing) that the maximum size is 32,000x16,000 pixels. I wouldn't be surprised that if you're close to either of those, the export becomes very iffy because of memory issues.
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