The action does not exist or you do not have sufficient privileges to view it

I know this is an older post and has been resolved but in case somebody else finds it googling for the issue and it isn't a permission setting I'll give an another solution.  If you are using the action outside of the context of a particular record, be sure you are using the process configured as a Record List Action instead of a Related Action.  It will throw the same error. 

I know this is an older post and has been resolved but in case somebody else finds it googling for the issue and it isn't a permission setting I'll give an another solution.  If you are using the action outside of the context of a particular record, be sure you are using the process configured as a Record List Action instead of a Related Action.  It will throw the same error.