How do I use the fill gallery to create a background?

[Cassie]

it keeps saying "unable to apply the selected thumbnail's properties to the image. Thank You.

[Bobm03]

What type of image - RGB True colour? Grey scale?
What kind of image - .jpg? .tif? bmp?

[roa3]

Im using PI XL...

how do you apply the background??

For me...
I'll draw the shape i like, then i apply the background and it works 100% fine everytime...