I am most definitely NOT an expert in this, but I'm pretty sure that "String Length" refers to the length of the file name/header and has nothing to so with the size of the actual file you are trying to use.
If you can download these images to your computer, have you tried renaming them to something rather shorter than their current names? Does doing so allow their import to PGD?
The file name has the same number of characters as other files that encountered no problems. However, I was able to import both files in Xara12. I'm using Version 18 but keep Version 12 as a backup. One of the files uploaded fine. The other had strange graphic elements in the image. Thanks for responding.