Trouble viewing/saving screenshots

[Double_J]

On Retropie 4.4, when I am playing a game, I can open the Retroarch menu and take a screenshot. It seems to take and save the screenshot. I hook my computer up to my pi through network and go to RETROPIE\configs\all\retroarch\screenshots and I can see the names of every screenshot I have. But nearly every time I try to open one and view, my computer will say that it can't read the file. Randomly (and rarely) it will let me view a screenshot. I don't know why this is happening. I am using Raspberry Pi 3 b+ and my computer is Windows 10 if that helps. If someone could help me, it would be greatly appreciated. Thanks

[mitu]

@Double_J Can you try transferring the files first on your PC and then open them ? Can you upload such an image somewhere to take a look at it - maybe RetroArch saves an incorrect .png image ?

[thelostsoul]

@Double_J Do you use WIFI? As mitu suggested, try to copy the file to your pc first and then open them and upload such a suspicious file, so we can see if we can open it.

[Double_J]

@thelostsoul I copied the file into my saved pictures folder on my PC and attempted to open with Microsoft Photos, but it says "We can't open this file." If I try to upload it here, I get an error message that says "input file contains unsupported image format" and this is what is uploaded:
Here is a screenshot that worked even though I did the exact same thing:

They are both .png files

[thelostsoul]

@Double_J I had some issues on my Linux machines with specific applications or uploads, when the file ending was not in lower letters. Not specifically with screenshots, just saying I had this experience where I had to change from .PNG to .png ending or from . jpeg to .jpg.

[Double_J]

@thelostsoul They all end in .png I've tried changing them to .jpg as well, but that didn't help. I should also maybe mention that when I go into RETROPIE\configs\all\retroarch\screenshots with my PC through network, the not working screenshots show that they take up 0 KB of data, while that Mario World screenshot shows 12 KB. Also I took a bunch more screenshots and am getting better results now; more than two thirds of them are viewable, but there's still just random ones that don't work right.

[mitu]

@Double_J If the screenshot file is 0 bytes, it's obviously empty - hence the errors. For some reason, RetroArch creates the file but it doesn't save the contents correctly.

[thelostsoul]

@Double_J Could it be that the micro sd card is broken? If you can, make an exacty backup copy on a different micro sd card with same size and if it still happens, this could be ruled out. Off course only if you have one in spare.

[Double_J]

@thelostsoul Thanks for giving me an idea of what might be wrong. Unfortunately, the only extra micro SD card I have is 16 GB, while the one in my pi is 32 GB. It's not really that big of a deal with the screenshots though, so maybe sometime in the future I'll get another sd card and try that out. Thanks for the help.