Fg-optional-mp-files.bin
Rename it to fg-optional-mp-files.bin.old instead of deleting. This allows you to restore it if something unexpected happens.
It’s important to distinguish fg-optional-mp-files.bin from other FlightGear cache files:
| File | Purpose | Can delete? |
|------|---------|--------------|
| fg-optional-mp-files.bin | Multiplayer aircraft models (3D & textures) | Yes |
| terrasync_cache/ | World scenery (terrain, buildings, airports) | Yes (but will redownload) |
| fgcom_voice.db | Voice chat audio recordings | Yes (loses voice history) |
| .fgfsrc or autosave.xml | User preferences and joystick bindings | No (loss of settings) |
Do not confuse fg-optional-mp-files.bin with any system-critical binary. It is purely a runtime performance aid. fg-optional-mp-files.bin
Delete all cache files in the same directory:
Then, run a manual scenery check using FlightGear’s launcher → Settings → “Download scenery on demand”.
Never delete or modify cache files while FlightGear is running. Rename it to fg-optional-mp-files
fg-optional-mp-files.bin is not malware. It is not a hidden log file spying on you. And it is not a broken relic of an old install. It is a well-intentioned cache that makes FlightGear’s multiplayer experience smooth—until it grows too large or corrupts.
The golden rule: When in doubt, delete it safely. FlightGear will rebuild it automatically. Include this step in your regular simulator maintenance routine, and you will avoid 90% of multiplayer loading issues.
Now you know the truth behind one of FlightGear’s most mysterious files. Happy flying, and may your binary caches always be small and uncorrupted. Then, run a manual scenery check using FlightGear’s
Have a persistent problem with fg-optional-mp-files.bin even after deletion? Visit the FlightGear forums or the official bug tracker at code.google.com/p/flightgear/issues/ — include your fgfs.log file for better assistance.
The file "fg-optional-mp-files.bin" seems to be related to a specific context or software that isn't widely recognized or documented in public databases or literature as of my last update. However, I can attempt to provide some general insights or potential leads on how to approach this topic.