There're thousands of add-ons on the Web for the classic FSX and Prepar3D v1 to v3. Take off from anywhere in the world, flying some of the world’s most iconic aircraft to any one of 24,000 destinations.
If this happens with a lot of addons, I have two questions for you:
[*]Have you already tried to reinstall FSX SE from the scratch?
[*]Can you provide an evidence of the error you have faced? Attach an image with the error to your response. Maybe more simmers can view this topic and help.
Go into fsx.cfg and delete any entries for concorde gauges etc then see if it loads ok - ignore all messages to re-allow the gauges. I often found a certain full dump gauge causes issues with 3rd party addon aircraft in FSX