When I try to save my psd it says Could not save “(File Name)” because the document exceeds the 2.00G limit for saving Photoshop files. See Help topic “Saving and Exporting Images” for more information.

Hi I had the same problem,  just sharing my solution.

So I wanted to save my file as pdf file with high quality, I solved the problem with the  trim option to reduce the file size and it worked well gd luck 👍 

I receive same error. There is Doc: 24,8M/129,3M in the left bottom corner. Saving as .psb works, but file size after saving is just 65,2 MB. Where is that more than 2 GB ??? If I open this 65,2 MB psb file and try to save it without any changes as .psd again this error about more than 2 GB. Sorry Adobe, but it doesn't make sense, is it?

Pasting a file into a Photoshop document, might be the problem, not Photoshop if that file has "Document Ancestors".

https://community.adobe.com/t5/photoshop/larger-file-sizes/m-p/10905114?page=1#M304064

Because Photoshop is trash.  I have a 1.4gb project opened.  I paste a 45 MB image into it and the filesize is now 9.5GB.  I then immediately delete that layer and boom, now it's only 9.48 GB.  Thanks photoshop!  Photoshop is trash.  I have 50k hours in this program, and it is broken beyond belief.

https://www.behance.net/gallery/70327097/Star-Wars-Episode-9-mockup-poster

I created this a year and a half ago in photoshop.  it has over 2500 layers and is right about where it belongs at just under 4GB at full 36x24 300dpi print resolution.  The file I am currently debating whether to throw my laptop out a window over is a 1 page website with not even a 10th of the amount of layers and is broken.  Get your house in order adobe.

One simple trick that may work is to crop your image to the final size which gets rid of any size-hogging material that is not relevant. For example, I added snowflakes to a photo using the noise filter. I had to scale that layer up 800% which caused the file size to explode from 100M to 7G. I only needed the effect on the original size so cropping it removed 90% of the layer. File went back down to 109M and saved normally.

I, too, have gotten this message, even though my document has only 2 layers and the document size in the bottom left says "Doc: 260.0M/520.0M." It's nowhere near 2GB. Why does this message continue to appear? I shouldn't have to save my 520MB file as a PSB.

Guys sometime it will continue to show you that error even after sliding the file handling and stuff. Best way is to go to Image on the top and click Image Size, decrease the height and width pixels (check the proportion box in the bottom). On the right you will see the image size to go down. This gives enough room for upcoming layers to fit in that size.

Save your file as a PSB or "Large Document Format". 2 GB is the PSD size limit.