Thank you Linc,
The solution was a different one however.
I discovered that one of the address book entries was causing the crash. This entry also caused the browsers on both my Mac and a windows computer to crash when I tried to edit it in the cloud online here https://www.icloud.com/#contacts
I duplicated the name of the entry, online then exported a back up and once that was safely completed I proceded to delete everything in the cloud. Once I imported the new info into cloud online and it synced with my iMac I was able to delete the old troublesome entry as a duplicate.
This has solved the problem.