Hello - I’ve got the exact same issue. Freeflight returns to the first flight setup.
Hi ! Cant find any folder under username\appdata\local\pckages\Microsoft.FlightSimulator. There is e and then g under the lot of MS stuff
Thank You @Hester40MT - Found the files under the Steam roaming profile. Worked great when they were deleted 
SOLVED!!!
It’s known that the problem appears when using non-english characters in windows user name because the sim can’t find the custom flight folder when you are setting up a new flight.
I’ve resolved the problem activating, in my Windows 10 (build 20H2), the “Beta version: Use UTF-8 for language compatibility” checkbox.
To do that, you have to go to “Control Panel” → “Clock and Region” → “Region” → “Administrative” Tab → “Change system regional configuration…” → and check the “Beta version: Use UTF-8 for language compatibility” checkbox.
After that the problem doesn’t appear anymore and you can set up a new flight without any problem.
Sorry, I couldn’t check that in other Windows versions.
Thanks for this tricky solution! Finally works to change airport without any problems!
Ohh… I’m going try this solution! Happy new year mate. Thank you…
Thanks for the permanent solution. It works without any problem!
Finally someone figured it out!!! This fix everything, from freeflight to missions!!!
Please @Beechc23 or @Hester40MT, this is the actual fix for the problem, mark it as Solution!
Congrats @CaptKennintong and thank you!!!
@Hester40MT it works!!! Finally fixed!! Thank you mate!
Great job!!! Fixed!!!
Unfortunately, I got this problem after activating Beta: Use Unicode UTF-8 for worldwide language described here:
After deactivating Unicode UTF-8, everything worked normally with the navigation! So I use the previously described solution:
To delete the 4files. User / name / AppData / Local / Packages / Microsoft.FlightSimulator_8wekyb3d8bbwe / LocalState / MISSIONS / Custom / CustomFlight / CUSTOMFLIGHT.FLT & .FSSAVE & .PLN & .SPB
When I’m creating a new flight plan I’m unable to proceed with it and it opens the previous flight plan. For example if first set a flight from LELL to LEBL, this goes fine. But then if I set a new flight plan from LEIG to LERS it appears LELL to LEBL again. I’ve found an unelegant way to solve his by deleting the previous flight plan on AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalState\MISSIONS\Custom\CustomFlight
But I’m not sure if there’s another way to do that straight forward or some configuration that I’m missing.
Any help will be deeply appreciate Ü.
Thanks a lot, I followed the steps and now is working properly!!!
I can’t change my Starting location on the world map.
Plane always starts at the first location i used as starting location.
very frustrating..
Planing a new flight didn’t work either.
There is some info on some websites regarding the Win10 Username for causing this issue.
Best regards,
Harry
Does that happen if you pull in a flight plan from outside the sim i.e. something from SimBrief or LittleNavMap?
I had the same problem. The Microsoft team are working on solving it.
But there is a work arround. In:
C:\Users\your name\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalState\MISSIONS\Custom\CustomFlight
Delete the file CUSTOMFLIGHT.FLT (just leve the otheres) before you start the simulator
You have to do it every time you start from the globe-menu.
Stay safe!
But this conflicts with the following: https://forums.flightsimulator.com/t/citation-cj4-and-apparently-all-other-planes-not-following-flight-plan-loaded-from-world-map-planner/321408/18
And there you should instead uncheck Use UTF-8 for language compatibility “checkbox”!
Your suggestion solved this problem for me. And of course. Why have we not thought about it something before. It’s actually a children’s lesson for any programmer. But who would have thought that it was the alphabet problem that in 2021 caused problems in a microsoft program?
Incidentally, it also solved another problem for me:
Now it all works again. And my machine has become noticeably faster in performing the various processes.
Thank you very much. In my case, it was the use of “æ” that gave the problem.
Hi @Hester40MT ,
Thank yo! That solved my Problem. So i did not need to delete the temporary *.FLT file.
Thank you, too @BlondeAcrobat62 .
Best regards,
Harry
Wow!! Thank yo! That solved my Problem. So i did not need to delete the temporary CustomFlight.FLT file.
Thank you.
Best regards,