Just signed up yesterday, so maybe it's actually a permission problem for the moment. However here is how to reproduce the error for me:
- Set up a couple of servers under http://dayz-ast.com/server/list
- Make sure you're set up as admin for the new server(s)
- Make sure admin permissions are set to "full access" under permission group
- Go back to main page: http://dayz-ast.com/
- Select one of the new servers from the drop down menu in "servers"
- Click on them and it will stay on the main page with a red error message on top saying "You don't have permission to perform this action." (It generates links like this one: http://dayz-ast.com/?_fid=19vm. However the links are correct when hovering over them in the menu http://dayz-ast.com/server/view/XY).