FSX, Prepar3D or FS2004: an installed add-on is missing

A completed installer may have targeted another simulator or an old folder. First identify the installation that received the files.

1. Close the simulator and reread compatibility. Distinguish FS2004, FSX, FSX Steam and the supported Prepar3D versions.
2. Check the installer’s destination and instructions. Do not substitute Community: that folder belongs to MSFS, not these classic simulators.
3. Restart and look in the appropriate place: aircraft selection for an aircraft, the modified location for scenery and the base model for a livery.
4. For scenery, follow the registration or activation instructions for your simulator version.

If the destination was wrong, use the add-on’s uninstall procedure before installing it correctly. Keep personal files added separately.

If content remains missing, include its page, exact simulator, selected folder and installer result in the comments. The troubleshooting-information guide helps you prepare the message.