Finally got automator and calendar to work.
I have had a lot of trouble getting my automator app's to trigger using calendar and I think i got it.
1. Make sure you start a new calendar on your mac NOT iCloud.
2. Open automator and create a working workflow.
3. Save workflow as a App.
4. Open system pref and select security. Under privacy allow new app to access or control your computer.
5. Go to calendar and create a new event in the new calendar you created on your mac. (There may be a calendar called automator already this is fine)
6. Under the edit event menu select alarm-custom-open file- select app you saved in automator-select at time of event.
FYI you can repeat this action if it something you want to repeat daily hourly ect
If your workflow won't run in automator it will not run in calendar.
MacBook Pro with Retina display, OS X Yosemite (10.10.4)