ePub error on GooglePlay

I updated to the newest version of Calibre last night. I'm getting an error from GooglePlay that I've never seen before. (I've done about 90 books with them.)

Required: Fix Image Issue in ePub
Misc/preview.wmf

Sigil is showing this on line 11 of each split:

<link href="../Misc/preview.wmf" rel="Preview" />

I tried deleting it in each split and Google is still rejecting it. It's passing the ePub validator check.

Any advice?

Kim Guidroz