Fix Key error :Key cannot be the null string

When you get this error message, that mean Barnes & Noble  account info you input isn’t correct,  this is tutorial how to find correct info for a book.

  • Your Name: This is the name used by Barnes and Noble to generate your encryption key.
    Seemingly at random, Barnes and Noble choose one of three places from which to take this name.

    Most commonly, it’s your name as set in your Barnes & Noble account, My Account page, directly under PERSONAL INFORMATION.

    Sometimes it is the the name used in the default shipping address.

    sometimes it’s the name listed for the active credit card.

    If these names are different in your Barnes and Noble account preferences, suggest try them one by one.

  • Credit Card#: this is the default credit card number that was on file with Barnes and Noble at the time of download of the ebook to be de-DRMed. Just enter the 16 (15 for American Express) digits.
  • Credit Card Number don’t need any more after NOOK Key created.

**if you don’t find billing address in order, that mean it is default address.

NOOK Color

World’s Largest Bookstore
Over 2.5 million titles-new releases to bestsellers. Sample FREE. Most $9.99 or less. Get them instantly via Wi-Fi®- usually in under 10 seconds. NOOK Daily Find™ brings you a great book at a great price, plus a weekly Free Fridays™ title.
World’s Most Advanced VividView™ Touchscreen
Ultra-responsive 7-inch multi-touch screen displays 16 million colors ultra-bright. Specially designed for remarkable clarity and minimal glare so you can enjoy the ultimate reading and entertainment experience.
Thousands of Must-Have Apps
Enjoy the best apps. Games like Angry Birds & SCRABBLE©. Essentials like Taptu & MyCast Weather. Favorites including Epicurious & Drawing Pad. Plus pre-loaded Sudoku, Crosswords, Chess & Pandora®.
Expert Recommendations
Get expert recommendations from our 40,000 booksellers, plus personalized recommendations based on books you love. And any time you’re reading, just tap the Discover icon for ideas on similar books to read next.

VBK to PDF – Vitalsource Downloader Mac

New Vitalsource Downloader Mac v2.0 is Safari Extension, it work with Safari browser, download Bookshelf book to pdf with 1-click, this is step by step guide.

1. Download, install and run Vitalsource Downloader Mac.

click “open safari extension preferences” button to turn on extension in Safari.

Edit website

2. Open book in Safari, wait it ready to download

In safari, open a new Safari window by Menu “File->New Window”,

in App, when Extension turn on, it show above image, click “Goto Vitalsource” to login Bookshelf, open book,

login Bookshelf in Safari browser, open book,

When App get information about book, it show above image, it is ready to download.
if App doesn’t get book info, click “Reload book” button to reload page and send book to App,

3. Download book

Switch to Safari, click icon in Safari toolbar to popup window, click Download button to start downloading,

it will go through all pages one by one, if Page stuck over 3 minutes, click “reload book” button to resume download,

user also can stop it anytime to take one day break, next time open same book and download rest pages.
if captcha show up, user clear captcha and downloading will continue automatically .

4. Build book

when all pages downloaded, it will create pdf file and show PDF path,

5. Turn off Extension

Turn of extension in safari Preference Extensions tab, Bookshelf app may close itself.

How to convert Kindle AZW MOBI AZW3 KFX to EPUB/PDF/RTF/TXT format?

if you want to read Kinde .azw .mobi ebook in Nook e-reader or other device, you must convert it to epub/pdf/txt format that supported by other e-reader, this is step to step guide to convert Kindle DRM ebook to PDF ePub Html word Text format.

Kindle Converter is tools to convert Kindle ebook to EPUB/PDF/TXT/RTF format with 1-click. it support Kindle DRM ebook downloaded in Kindle for PC.

Video Guide : convert .azw .mobi file to PDF/epub/word/text format

1). First, download and install amazon free app Kindle for pc or Kindle for Mac, converter support kindle for pc v2.0, we can remove drm from kindle unlimited book downloaded in v2.0.

Download Kindle for PC v2.0 Download Kindle for PC 1.17

2). Download ebook in Kindle for Pc.

Video tutorial to download Kindle ebook into Mac Windows

Run Kindle for PC, right-click title to download ebook in Library list.

3). Run Kindle Converter, click Kindle button to add all azw files into file list in converter.

You also can drag azw file from windows explorer to converter, azw file saved in “My Kindle content” folder.

  • For Windows, files is saved in “My Document\My kindle content” folder.
  • For Mac, it is “~/Library/Application Support/Kindle” folder.

4). Select output format in Output Section button, you can select pdf,epub,rtf, htmlz,text format in drop list, change output folder if you want.

5) Click Convert button to start job, wait until all job done, if everything goes well, new ebook files will be created in output folder, click Open Output folder to find them .

6) Sending your new e-book file to your e-reader .