Pattern fills in CorelDraw 2017 won't render

Hello there. I am having a continuing problem with pattern fills in Draw 2017, which was sporadically the same in X8 and in X7. I create a new simple rectangle, fill it with a solid colour ... no problem. Edit to a gradient fill, as complex as I like ... no problem. I then try and edit the fill to a pattern, any pattern type. The fill dialogue at the bottom right of the workplace shows the selected fill in place, but the rectangle remains obstinately empty. I'm looking at the result in enhanced mode, so it's not a wireframe problem. I restart Draw 2017 using the F8 key, and agree to reset to factory defaults, which means I lose all the nice bells and whistles I've installed on the workspace to make life easier. I repeat the process with the rectangle, and the fill shows up perfectly. Eureka, I cry!!! However, I close the document, then close Draw. I reopen Draw to a new document, and the expletive rectangle does not show the selected pattern fill again. This is driving me crazy. I open an older file from I think X6 with a pattern fill that I know works, copy a filled shape from that document and paste it into the new 2017 document ... it shows up perfectly!! I then try to edit the pattern fill in the pasted shape, it works perfectly!! I do a lot of anatomical type drawings for PowerPoint presentations and in Flash animations so the pattern fills are a great resource, but in Draw 2017 they don't show up as rendered unless I go back to an older version drawing and copy one into the 2017 document then use the right mouse "copy fill" shortcut to clone the fill to the new rectangle (or whatever shape) and then use the Edit Fill tool. "Virgin" rectangles still do not show the patterns from scratch without that work-around. Can anyone please help ... before I move back to Illustrator, from which I moved to Corel in the early 1990s? Thank you.