Flight Simulator error after repairing acceleration

Hello,
My simulator gives me the following error message after repairing acceleration and shows “Flight Simulator requires at least one each of the following to run: an airport, a VOR, an NDB, and a waypoint. There is currently no airports in the dataset. Flight Simulator will now exit”. This is very weird and unknown to me. How can I fix it? Suggest me. Thanks.

Flight Simulator requires at least one each of the following to run: an airport, a VOR, an NDB, and a waypoint. There is currently no airports in the dataset. Flight Simulator will now exit.
