"Add to swatches" = " Swatch Cannot Be Created"

[JohnWalker]

I am using PSP X5 (15.3.0.8) to try to create a new Pattern Swatch from a flattened image. (Single layer, no vectors.) The particulars:

- 512x512 Pixels
- 72 PPI
- RGB 8 bit
- .jpg or .bmp

I click on the foreground in Material Properties, select the Pattern tab, select my image, and then click on "Add to swatches..." whereupon I am consistently presented with:

"A swatch cannot be created from this material for the following reason(s):

The pattern has not been saved."

I don't know if the second line of text is the reason (the file is saved), or if the real reason is supposed to appear where the blank line is.

I can add Color and Gradient swatches just fine. I restarted the app several times, even As Administrator.

I suspect that I am missing something blatantly obvious, but turned up nothing even after a good couple of hours of reading everything even remotely related online.

I will be grateful for any ideas.