This is the line that has the error.
Code:
<tr data-calibre-jacket-searchable-tags="1" style="color:white; display:none">
Remove data-calibre-jacket-searchable-tags="1" and the error goes away.
This error is only an error with ePub 2. It verifies with ePub 3. But (IMHO) that bit of code is not needed and if it goes away, the jacket is good on both ePub 2 & 3.
One other issue. If you do not select to put the jacket at the back, it's put at the front where the cover should be. So that chages the cover since the cover should be first.