I'm in dynamics crm 2011 on prem and I have no idea what happened to this button however I want to fix it.

Currently when you click the button on the ribbon, it throws an error message,

I have a test environment, and the button works fine....
I have Workbench Ribbon installed and I am fairly decent with it BUT I am unable to locate which entity it is I need to edit... I've tried Engagements, Services, and Engagement Calendar, Meetings and no buttons.
I know at the top right corner in Workbench Ribbon there is a homepage, form section which I tried both.
I was going to try and restore the button to match the test environment button and see if that worked, if not, I was going to come back and ask for additional assistance or just remove it but I'd really rather not remove it...
Thanks much,