According to that debug log, your device is running Android 4.4 (Kitkat). It also appears that your books are on an SD card (/storage/extSdCard/Calibre), but not in the Google-approved directory on the SD card. In any event, CC fails to open and write the book file. It isn't clear whether CC is failing to create the subdirectories or the file itself.
See our FAQ answer "
How do I use an SD card with Android 4.4 (Kitkat)"