Gigapixel doesn't save the images

I’ve been trying to do patch editing with Gigapixel, but it seems that without any apperant reason, many of the images won’t be saved at all. Instead I will get that red X icon symbol and the image is not produced. Then sometimes, with some other image and same settings I suddenly get the image produced. What would be the reason for that behavior?

Image of what the queue looks like:

I am still having the problem. Am I actually the only one who is having this problem? I don’t know what’s the difference between the images the program saves and the ones it doesn’t. All of them are png files and sometimes the original images also are in same size.

The previewing works very well with those and all of the images.

Addition. It’s not about the file itself, because I opened it in photoshop and saved again, which didn’t heal the process.

If someone else has this problem, it’s because the file names were too long.