I have never heard of that organization. I have even Googled it but couldn't find any information about such an organization. I also tried finding a location abbreviated "CAO", but I could find nothing. I guess only the support team can explain what that means. From the error text, it looks like it is a geographical restriction, but confirming it from the official source is always better.
Even if it's a geographical restriction, it's probably from the game provider and not the platform itself, I believe.
According to their support agent, CAO stands for Country Authorized Operations. I sent them a screenshot that displays the error when accessing a slot game which means the game is not available in our jurisdiction. Some providers cannot offer certain games in our country due to license restrictions. They do not have influence on that. Sadly she does not know the specific reason for this.
Sadly some contact agents lack the basic information about some technical terms and info on certain thing that is why few of them tend to give out misleading informant about questions on those things, so the best thin to do is that, when an agent failed to give you the correct information, you are free to do your own extra findings most especially, when it comes to issue's that borders on games restrictions and regional regulatory requirements this belong to the legal team of the casinos.