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In order to administer the website your role should be Administrator.
Please let me the below information to help you with the situation:
1) Do you have Ct CS3 installed? If yes then do you have the connection of your website in Ct CS3 and are you able to administer it right now?
2) Are you getting any error while creating the connection in Ct 6.5?
3) If you are able to create a connection in Ct 6.5, do you get the window where you can choose the role (as Administrator) for you, while creating the connection?
My role is the administrator. To respond to your questions.
1) I have Ct CS3 installed and a connection to my website. I can also administer the site using Ct CS3 without any problems.
2) Yes, when I try to create a connection using Ct6.5 I get the above error. I also try using a connection key and unable to connect. I have tried other websites on this same server and have been able to successfully connect using ct 6.5 but those sites had never been updated using Ct.
3) Unable to make connection. It stops me there.
I have included a snapshot of the error message.