Could not find/access simulator

I have installed the newest beta and it worked many weeks perfectly. but now i wanted to update the nav data to the new circle. i clicked “remove” -> it worked. then i clicked “install” -> it created the navgraph-data-folder in my community folder, and then it shows “could not find/access simulator” (i think it wanted create the backup of the simulator nav data). additional information: i have the microsoft store version of the sim and it is installed on drive “f:” and not on the windows system drive “c:”.

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first of all: HAPPY NEW YEAR 2021 …

Thanks for contacting us and the report. May I ask, what client beta version you have still in use? The latest one beta 19? You see this on the bottom line directly in the client.

When you not have beta 19 installed:

  1. close the sim
  2. start the client and remove the AIRAC dataset
  3. close the client and download/install the current one
  4. start the new installed client and install the AIRAC again
  5. start the sim and look, if you issue is fixed

Thank you,

Hi Richard.
I wish you all the best for 2021!
I am using Beta 19.

Hi Torsten,
no, we don´t create any backup of the stock data because we don´t delete anything physically - our data work like an overlay so this error message has nothing todo with a backup but with the installation.

You wrote, you have installed the sim not in the default C drive. Possible you have a rights-issue. Can you look on this posting from Markus, our developer for the client?


Unfortunately it didnt helps. I have all rights in every folder and subfolder checked. And I tried to run the Beta as Administrator without success. Navigraph creates the navdata folder inside the community folder and then it shows the error message. the folder maintanance is not created anymore. And the button does not change from Installing to Remove.

Same problem here. After a fresh installation of the navigraph app I get the same error message. I have all the proper rights I need.

Hello, I´d like to bring the topic back into focus. I´m having the same problem as Aerokruemel. The app worked perfectly until two days ago. My sim is installed on harddrive f:. Has the app code been changed in the last couple of days?

I see exactly what AeroKruemel described: the app only creates the navdata folder in the community folder, but no maintanance folder. Then it stops and reports it can´t find/access the simulator and that´s it. A logging function would be great. I´ve tried everything I can think of to get it to work.

I´d appreciate any suggestions! Or could I try an older beta version of the app to see if that works?

@NAVData do you have further advices/ideas?

Hi guys,
I´m still believe, that you have a rights issue somewhere. The error message said exactly that …

The strange thing is, that you both are speaking from the “maintenance” folder. This folder doesn´t exist anymore since 5-6 updates. So, therefore I´m not sure, that we really speak from the same. Therefore please a few requests, and please do it exact in this order, even you had done this before:


  1. close the sim, close the client
  2. uninstall the client via the normal windows feature “Add or remove programs”
  3. download the latest client version beta 19 from here
  4. open the client and either remove the installed AIRAC (when the remove button is available), or install the AIRAC now

When all is done and it´s working … no further tasks necessary but when not:

  1. post a screenshot of your rights from this folder:
    C:\Users\<your user>\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache

  2. also a screenshot of your rights of the UserCfg.opt file

  3. a screenshot of your community-folder

  4. a screenshot of your client, after you have pressed the install-button

  5. a last one, with the content of the navigraph-navdata folder in the community-folder:

Thank you very much,

Thanks for the detailed answer.
Unfortunately it does not work.
Windows/System installed on C:
FS2020 and the Community-folder are installed on F: (on C only some links exists; I used the “Move APP to another directory”-function of Windows)
NavGraph-App installed on E:

Here are the asked screenshots:

LocalCache(-Link) on C:

LocalCache-folder on F:



Created navdata-folder:

Thanks and best regards,

The 2 additional screens:


Navgraph installation folder:

Hi, thanks for your feedback!

After waisting more time trying to fix the problem and running into more problems, I‘ve decided to completely de- and reinstall the sim. Now everything works the way it should. I probably did have a hidden rights problem, but I wasn’t able to detect it.

Before everything had been messed up I deinstalled my virus scanner and messed around with the freeware Addons Linker. Something happened during that process I wasn’t aware of.

Like I said, a fresh copy of MSFS did the trick. The problem obviously had nothing to do with your installer.

Sorry for the confusion!

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Congratulation, but my question is still open :slight_smile:

… but @AeroKruemel you are writing you use also a tool to move the sim to another location. I guess also, that this is the issue here.

Thanks for your feedback - yes, we also have figured out, that these addon-linker programs are not so good for the sim. We can also bot explain in detail why and what happend but the sim is very, very sensitive with rights and therefore we also recommand only the standard way, which is recommanded from ASOBO/MS.

Good that ir’s solved now … You will see, you will now have a stable client.


No, I didnt used a tool. I used the standard Windows function to move a Windows App (FlightSim) to another location.

Sorry Torsten for the possible silly question :roll_eyes: but what feature is it? I would test it here on my machine


Hello Richard,
no problem. You can find it in the Windows-Apps&Features-List:


Danke Torsten … you never stop learning :slight_smile:

I have tested the “move” but I can´t reproduce it. The Navigraph Navdata client works after the move as expected. The only thing what I have made was to uninstall the client and reinstall it, but after that - no issues. Hm, I´m near my end of knowledge, why this doesn´t work on your end … possible someone in our team has still a new idea …

Sorry Torsten … we do our best!

Hi guys, im having a very similar issue. Installed navdata V23 in default location. comunity folder is on my E drive however all permissions are as instructed by NAVData above. The one thing i dont not see is a navigraph navadata folder in my comunity folder.
When i load up to install latest AIRAC i get the could not find/access simulator.

UrserCfg.opt shows comunity folder loaction correctly as well. Ive tried everything i found on the forum but still not able to get it working even after several uninstall and re installs.

Unfortunately I dont know a solution or the reason. But I found a workaround: I have to move all other mods from the community folder. Then I could Install the new AIRAC. After this I move all the other mods back to the community folder.