Feathered shape does not export to PDF

[Noel Williams]

I've been tearing my hair out with frustration trying to produce a PDF of a large banner for our printer. I keep getting 'Access violation exception at offset 0x0201CF15' when trying to use the Commercial Printing option. (I get no message and no PDF with the High Quality setting.)

By a process of elimination I discovered that the problem is caused by two simple coloured blocks with feathered edges.

I deleted all the other elements of the design so this is now a tiny file.
Can anyone else get this file to export to commercial quality PDF??

I'd be grateful for any advice.

Noel Williams