I just upgraded to 4.7.28 on wordpress 4.9.1 I am trying to setup my Clickatell SMS provider but I am getting a strange error;
However I have dobble checked the details and have tested it using the URl method:
and that work fine, I am just trying to send indervidual SMS's at the moment.
here are the setting I am using:
Any help or insight into where things are going wrong would be appriciated