Board Thread:Support Requests - Designing Your Wikia/@comment-25263848-20140807182900

I have uploaded a watermark image (png with transparency) using the themedesigner, in the themedesigner preview its background was transperant, but after savinig the background is black. I look at File:Wiki-wordmark.png its background is black.

What is this happening and can I replace the File:Wiki-wordmark.png manually with original file with transparent background? 