[Doitsu]

The first two problems are related to Pillow and the last one is an actual bug that I'll fix in the next plugin version.

Try the following workarounds:

1. Delete or comment the following section (lines 116-119)

Spoiler:

        # /Applications/Kindle Previewer 4.app/Contents/MacOS/lib/kindlegen/fc/bin/kindlegen [*** for future versions ***]
        default_osx_path2 = os.path.join('/Applications', 'Kindle Previewer 4.app', 'Contents', 'MacOS', 'lib', 'fc', 'bin', 'kindlegen')
        if os.path.isfile(default_osx_path3):
            kg_path = default_osx_path3

2. Delete or comment out the following section (492-500):

Spoiler:

        # look for cover image
        cover_id = None
        cover_item = opf_soup.find('item', {'properties' : 'cover-image'})
        if cover_item:
            cover_href = cover_item['href']
            cover_id = bk.href_to_id(cover_href)
            cover_def = os.path.basename(cover_href)
        else:
            plugin_warnings += '\nWarning: Cover not specified (cover-image property missing).'

3. Delete or comment out the following section (lines 555-569)

Spoiler:

    #------------------------------
    # check minimum cover width 
    #------------------------------
    img = None
    if cover_id and os.path.splitext(bk.id_to_href(cover_id))[1][1:].upper() != 'SVG':
        imgdata = bk.readfile(cover_id)
        img = Image.open(BytesIO(imgdata)).convert('L')
        width, height = img.size
        if width < 500:
            plugin_warnings += '\nWarning: The cover is too small: ' + str(width) + ' x ' + str(height)
        # check recommended dpi
        if prefs['check_dpi'] == True:
            xdpi, ydpi = img.info['dpi']
            if (int(xdpi) or int(ydpi)) < 300:
                plugin_warnings += '\nInfo: Amazon recommends 300 dpi cover images. Your image has: ' + str(int(xdpi)) + ' x ' + str(int(ydpi)) + ' dpi.'

3. Make sure to also uncheck the Generate Thumbnail option in the GUI.

With these changes in place you should be able to run the plugin again.