Please right click on the cover image of the book in your library and select "Item Info". Then select the arrow button that will show the file in Explorer.

Explorer will open and the file will be highlighted. Please click once on the file name to edit it. Shorten the filename to a reasonable length (under 20 characters). Please also remove any special characters.

Once you have done this you will need to re-add the book to your library. Right click on the cover image in your library and select "Remove from Library", then "Remove".

Then go to File > Add to Library. Then navigate to the newly renamed file, select it and click 'Open'.

If you still receive the message please complete our support form to submit a ticket to our customer support. Please ensure to quote the error message in full in the support ticket, and the name of the book that is causing the problem.