The only way I can replicate your repeat message is if I have FSX running but have not started a flight session (still in the opening menus).
Before trying to connect from ADE, you must start an FSX flight (Fly Now), preferrably at the airport you are going to edit. You should be in 'Slew' mode (press Y to toggle 'Slew' mode).
If you've already done this and are still getting the repeat message there may be a problem with simconnect or other required element:
-Run the ADE Environment Checker (Start>Programs>Airport Design Editor 9X>) to see if it reports any problems.
-If you have updated FSX with any Service Packs, make sure you have updated the SDK as well-
http://www.fsdeveloper.com/wiki/index.php?title=SDK_Installation_(FSX)-Check that you have the latest version of ADE (ADE menu>Help>Check for update).
-Ask for help at the ADE support forum-
http://www.fsdeveloper.com/forum/forumdisplay.php?f=95-Though the author (Scruffyduck) stops by SimV, you might get quicker solution there. Include your FSX and SDK versions installed and your Windows version.
Dave
At that time [1909] the chief engineer was almost always the chief test pilot as well. That had the fortunate result of eliminating poor engineering early in aviation.