iMessage speech (applescript) timing out after upgrade to yosemite

When I receive an iMessage, chat or Message on my desktop (iMac), it is read out loud.

After the upgrade to Yosemite it does not work. I continue to receive the message that "AppleScript timed out." I click on "wait" and it will read it. This occurs when I SEND as well as when I RECEIVE messages, although reading aloud is only on receive. - I would love if someone might address this issue! It still works great on my previous OS version on my laptop.