|
Preferences->Behavior->Use internal viewer for: check ZIP
The factory setting for ZIP is unchecked
Calibre Ebook-Viewer dynamically converts non-EPUB formats to EPUB providing it's checked in that list, otherwise the OS file type association program is used to open the file.
Many (most ?) people who use Calibre convert most other formats to create an EPUB file, including ZIP, PDF being a notable exception.
BR
|