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Library Guides

E-books: Troubleshooting

Help! Why can't I access an e-book?

Some e-books only allow access to a certain number of users at the same time. You might see a message such as:

  • session unavailable
  • maximum user capacity reached
  • this e-book is in use

‚ÄčIf so please try again later.  Remember to sign out of a session after use.

Cambridge Companions / Cambridge Books Online 

Some books may be limited-concurrency i.e. only a certain number of users can access a given book at once.

When you have finished reading please close any PDFs from the site that you have opened in your browser.


You will need Adobe Digital Editions to download e-books to your personal computer.  If you are using a University PC you can use the 'read online' option, but you will not be able to download an e-book.

Use an up-to-date internet browser; you may experience problems using older versions.

Most e-books are unlimited access but some are limited to 1 or 3 concurrent users.  Publishers set the print and copying limits, as well as the download option so they vary from e-book to e-book.


If someone is already reading the e-book, you will see the message “Sorry, this Ebook is in use”. Please try again later.

Once you have finished reading the e-book, ensure you close your browser window.

If you are repeatedly unable to access the e-books you want, please Ask a Librarian via the Service Desk.

Why is there no print function on O'Reilly Learning?

You CAN still print, but you'll need to use the print function of your internet browser. There is no print button on O'Reilly Learning itself. 

Why are e-books from Amazon/Google not available in Library Search?

Some e-books may be sold only to individuals, via sites such as Amazon, but are not available for purchase by university libraries or similar institutions.

This is because the way publishers sell e-books to institutions such as a university is different to how they sell to individuals due to licencing and the number of users involved.

Need more help?

If you're still having problems accessing an e-book you want, please Ask A Librarian via the Service Desk.