If you have Sony's Reader for PC/Mac software, you may have accidentally downloaded a title to it when you meant to use Adobe Digital Editions (ADE). In this case, you can transfer titles from Reader for PC/Mac to ADE.
You may also want to set ADE to automatically open downloaded eBooks from your library.
How to transfer eBooks from Reader for PC/Mac to Adobe Digital Editions
- Open ADE, then go to File > Add to Library.
- Find the EPUB eBook you want to import, then double-click it to open the eBook in ADE.
You can select more than one by holding Control or Command and clicking each file.
The Sony Reader software stores EPUBs here by default: [My] Documents/My Books/Reader.
The title(s) you selected should now be added to your ADE bookshelf.