Launcher and LauncherHelper direct download for quarantined files


New member
Various antivirus (AV) software packages have been incorrectly flagging portions of our software as infected with a virus (read more about that here). It seems to mostly be affecting the DVD & Tower editions of RealFlight, not the Steam edition, so that's what this post addresses.

UPDATE: We believe we have a more permanent solution to this problem now which is currently available as a public beta update. But if you were affected, you may not be able to update at all until following the directions below.

The typical victims are not the main RealFlight application but a couple of side applications: the RealFlight Launcher and LauncherHelper. Sometimes one or the other is flagged, and sometimes both.

When that happens, the AV software usually quarantines the application(s) in question, meaning it removes it from its original location on your disk and shuffles it into a dark corner where it can't run or do any harm. That's supremely useful when it's right and is saving you from actual danger! When it's wrong, it can be frustrating or worse.

The thread referenced above contains some instructions for restoring applications after Windows Defender quarantines them, and suggests that other antivirus software should have some similar options. However, some users have reported that they don't have the option to restore the applications after quarantine. They're apparently just gone forever.

Unfortunately, users in that situation have no good way to recover. We are working on a better long-term solution to stop the false detection in the first place, but in the meantime, if you've tried the normal restore options to unquarantine your file(s), you can now download an installer package below that will replace them for you.

The Launcher and LauncherHelper that it contains have been digitally signed with a certificate that should help prevent them from being quarantined in the future.

Note that if you chose to install RealFlight 9 somewhere other than the default location, when you run the installer package below you will need to modify the installation path accordingly. Be sure to read the notes it presents after it starts up.

Version Compatibility
I've done a careful review of Launcher changes between recent versions and determined that the latest one from 9.50.024 should also be safe to use for 9.50.015 and 9.50.021. (This isn't always the case; sometimes it would be very bad to mix & match versions of the applications!)

However, if you're running 9.0 and not 9.5, stop here. You need more help, and these instructions do not apply to you. Similarly, if you're running a version later than 9.50.024, do not continue. (Hopefully versions after 9.50.024 will no longer experience this problem! If they do, I will update this post as needed.)

Downloading and Installing the Files
  1. Hopefully it will no longer be a problem, but you may want to tell your AV software to allow/ignore the Launcher and LauncherHelper to help reduce the risk of these files getting quarantined all over again.
    • The RealFlight Launcher lives here:
      C:\Program Files (x86)\RealFlight9\Launcher9.exe
    • The RealFlight LauncherHelper lives here:
      C:\Program Files (x86)\Common Files\KnifeEdge\LauncherHelper9.exe
  2. Right-click the link below and save the file (SignedLauncherFiles.exe) to your disk, then run it.
  3. Because Windows and some browsers are especially distrusting of executables downloaded from the Internet, you may get yet another warning when you try to run this installer. Unlike the original problem, it's not because it sees something it thinks is a virus. It just wants to caution you about running something you grabbed online, which can indeed be dangerous.
    • Browsers vary, but if Microsoft Defender SmartScreen complains, click "More info" and then "Run anyway" as shown in the attached images. (It may also suffice to simply run it a second time.)
The revised versions you have made available still trigger AntiVirus to quarantine them..


New member
Hey Guys, ill save all the backround info other than having owned all previous real flights up to 6.5, my son bought me 9.5 as a gift and as marcushh said I did buy a Dell G7 after researching what would work well, I only have widows defender and shut everything off to load but once up and running I get one or two plays and then I keep running into the (maximum number of allowed instances issue) at which point my launcher is done and the game will no longer play. I have wiped out and reloaded once on disc and twice on website per Bonnie at Horizon Tech support and start from scratch all over again but then the same problem again, PS I did do the update but not making a diff at this point. I am an on call Pilot 24/7 and love to bring RF everywhere I go to keep up my Heli skills but don't have all day to keep fixing this. Very Frustrated!


Active member
Honestly, if you cannot figure out something so simple to do I'm glad I don't need a ride in a real heli with you, lol!


Well-known member
once up and running I get one or two plays and then I keep running into the (maximum number of allowed instances issue) at which point my launcher is done and the game will no longer play.
@alewin6247 RealFlight is not a game; its RC flight simulation software based on FlightAxis flight physics simulation software. This is a huge distinction.

The reason you're getting multiple instances running is that you're relaunching (like a game) when you crash; but, the simulation software is not designed to do that; Rather, you need to reset, leaving the original (initial) instance running.

There are two primary ways to reset following a crash: (1) press the space-bar on your keyboard, and (2) press the RESET or CLEAR button on your InterlinkDX controller.

An instance is a single "run" of the simulation software... while its running if you launch another "instance" then you'll get the error you're describing. Before you launch a new instance of the simulation software, you must first EXIT the initial instance. The correct thing to do when you crash is to RESET with one of the two options listed above.



Well-known member
I hope that you have it figured out the problems by now. We once had a big fight in the forum when RF was called a game. I fall on the side of entertainment. This hobby is supposed to be fun. The program is not a great shoot 'em-up game but some use it thusly. That is fine by me. Some use it professionally to fly drones commercially. I use it both ways and welcome more users to have fun or learn. It is up to you. A great game teaches you and wastes your time. RF is both.
at which point my launcher is done and the game will no longer play.