First see https://aquaconnect.desk.com/customer/portal/articles/2371277-ion-desktop-client-error-unable-to-resolve-host-s-. If this does not solve the problem then Aqua Connect will need your help in diagnosing what is wrong by following these steps on the machine running Ignision SE:
Open a terminal by holding down the Command key and pressing the space bar. This will pop up Spotlight Search. Type terminal into spotlight search and press enter. This will open the Terminal application. Next enter the following command in the terminal (you can copy and paste it; make sure there is a space between "/Ignision\" and "SE.app/"):
Finally, e-mail the file named “ignision_log_files.tar.bz2” on your Desktop to Aqua Connect.