why does adobe digital editions quit when I try to load my ebook

I recently bought an ebook from a publishing company (Guildford) and need adobe digital editions ADE 4.0 and an Adobe ID to access my ebook.

I downloaded and successfully installed the mac version of ADE 4.0 and set up said Adobe ID, successfully verified my computer and it all works. I downloaded my purchased book into ADE 4.0 but when I click 'read' I get the unexpectedly quit apple command - error pathway says bad access - Can anyone help?

Process: Adobe Digital Editions [94415]

Path: /Applications/Adobe Digital Editions 4.0.app/Contents/MacOS/Adobe Digital Editions

Identifier: com.adobe.adobedigitaleditions.app

Version: 4.0.3 (1)

Code Type: X86-64 (Native)

Parent Process: launchd [189]

Responsible: Adobe Digital Editions [94415]

User ID: 502

Date/Time: 2015-03-03 14:51:41.231 +1300

OS Version: Mac OS X 10.9.5 (13F34)

Report Version: 11

Anonymous UUID: 7DBA6C68-D8BB-418A-64CF-6E9B86875870

Sleep/Wake UUID: A5D5BCEB-E3C3-4D2B-86A2-81F0DB1F746A

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_BAD_ACCESS (SIGSEGV)

Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000