On upgrade this morning to version 2.6, the theme previews are broken. I am using the setting "As a showcase inside a page [Our Themes]," but the previews are also broken with the other settings (I checked). The broken aspect is the screenshots on the previewer page. The template screenshots are missing.
I tried the "repair database" setting on the Blog Templates settings page with no luck.
I will upload a screenshot of the previewer page.