Sim EFB - Troubleshooting and How it works

This page will give you an insight into how SIM EFB works and should help resolve issues.

We also have additional information on our Support forum and please read the Instructions which included training videos.

Problem: The program CRASHES

A virus checker or malware protection software is killing Sim EFB manager (simEFBmanager.exe), suspecting it is suspicious.


Exclude %APPDATA%\Local\simEFBmanager\simEFBmanager.exe from such software

Google "how to exclude program from windows defender" or the name of your particular protection software

Problem: I see no content in the SIM EFB Panels

Sim EFB manager (simEFBmanager.exe) contains a mini webserver to provide the content to the Sim EFB Panels.

First try this

To produce the content in the SIM EFB panels within FS2020, Sim EFB manager (simEFBmanager.exe) MUST BE RUNNING.

If you see:

Press the hidden button, which appears when the mouse is over it, at the top of the window to refresh the Panel:

If this fails, read on…

The most likely cause of this problem is a virus check, firewall, or similar protection software, blocking the web server access. Re-installing the software will have little effect, so please don’t waste your time.

The following shows the communication between SIM EFB and FS2020, which in terms of the Panels displayed which is quite simple.

The panels display the SIM EFB content by displaying the following web page:

      http://localhost:8081/content/index1.html and index2-3.html for panels 2 and 3.

Therefore, if they fail to display in FS2020 or an external browser, the SIM EFB mini webserver is being blocked on TCP port 8081.

The most straightforward answer is to %APPDATA%\Local\simEFBmanager\simEFBmanager.exe from any restrictions by virus, firewall or protection software.

Google "how to exclude program from windows defender" or the name of your particular protection software

Note this is communication internally within your PC, so you should not need to change anything on the router or external to your PC.

Remove/Reinstall Panels in FS2020

If the Panels do not appear in FS2020, the menu option "FS2020 >> Reinstall Panels" will reinstall them for you. See instructions at Publishing SIM EFB Panels to FS2020

FS2020 IMPORTANT: Addons are only detected when starting FS2020, so if addons are installed while FS2020 is open, they will not show until the next FS2020 start-up.

Remove Panels from FS2020

To remove the Sim EFB panels, click on the "FS2020" menu option withing SIM EFB which Enables and disables the panels.

Uninstall will also remove these folders

If this fails, manually delete folders "sim-efb1" to 3 from the "Community" Folder -

Finding The MSFS 2020 Community Folder

Where is everything stored?

Program Location


This folder contains the program, and other necessary files

Settings Location


The folder is not deleted during an uninstall to retain the license and settings.

Flight Plans


Stores all the flight plans in structured folders. Not deleted during an uninstall.


in windows file explorer type %APPDATA% . This will show the "Roaming" directory.

Then navigate back up one directory, and then to the "Local" directory

and next simEFBmanager-settings directory

to give: %APPDATA%\Local\simEFBmanager-settings

delete options.xml file

What does it do when first installed?

1) SIM EFB creates a directory in Documents called "sim-efb-flightPlans"

it then copies "Airport" and "FlightPlans" directories from %APPDATA%\Local\simEFBmanager\packages to the sim-efb-flightPlans folder. See screen shots above.

If this fails, then probably a virus checker stopping SIM EFB from doing this thinking it is Ransomware because it is writing a lot of file to the Documents folder.

Google "how to exclude program from windows defender" or the name of your particular protection software

How do I do xyz?

Please read the Instructions