Win32Exception when C# tries to launch executables that use .dll files

[jeremy-deutsch]

Environment

Run the following in your terminal and copy the results here.

1. npx react-native --version: 4.12.0
2. npx react-native run-windows --info:

  System:
    OS: Windows 10 10.0.19041
    CPU: (4) x64 Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz
    Memory: 5.76 GB / 15.89 GB
  Binaries:
    Node: 12.13.0 - ~\AppData\Local\Temp\yarn--1598140426848-0.5372970318084522\node.CMD
    Yarn: 1.19.1 - ~\AppData\Local\Temp\yarn--1598140426848-0.5372970318084522\yarn.CMD
    npm: 6.12.0 - C:\Program Files\nodejs\npm.CMD
  npmPackages:
    react: 16.11.0 => 16.11.0
    react-native: ^0.62.0-0 => 0.62.2
    react-native-windows: ^0.62.0-0 => 0.62.5
  Installed UWP SDKs:
    10.0.17763.0
    10.0.18362.0

3. reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock
    AllowDevelopmentWithoutDevLicense    REG_DWORD    0x1
    AllowAllTrustedApps    REG_DWORD    0x1

(using Visual Studio 2019, tried with Debug and Release build configurations)

Steps To Reproduce

Provide a detailed list of steps that reproduce the issue.

1. Find a path to a .exe file on your computer that depends on one or more .dll files in its directory. I was building a game launcher, so I've tried this with random games I have on my PC (e.g. Super Crate Box). NOTE: most paths on your PC don't seem to be readable/executable by Native Modules, but a path inside Program Files or Program Files (x86) should be.
2. In a fresh React Native Windows project with C#, add a C# Native Module to your project with a single method that calls Process.Start() with the path from step 1. Then, call that method from your JS code somehow.

The native module method should look something like this:

// top of the file
using System.Diagnostics;

// in the class
[ReactMethod("launchExe")]
public void LaunchExe()
{
   ProcessStartInfo startInfo = new ProcessStartInfo(@"C:\path\to\my.exe");
   Process.Start(startInfo);
}

Expected Results

Describe what you expected to happen.

I expect the executable to run. Instead, Process.Start() throws the following exception:

System.ComponentModel.Win32Exception: '{Illegal System DLL Relocation}
The system DLL %hs was relocated in memory. The application will not run properly.
The relocation occurred because the DLL %hs occupied an address range reserved for Windows system DLLs. The vendor supplying the DLL should be contacted for a new DLL'

Snack, code example, screenshot, or link to a repository:

Here's a minimal code reproduction: https://github.com/jeremy-deutsch/rnw_dll_repro

It doesn't include a .exe/.dll file combination (it'd be really weird to ask someone to run that). It just asks you to type in a path instead, and runs the .exe file at that path.

[asklar]

@jeremy-deutsch RNW apps are UWP and therefore follow app container rules (incl. not being able to launch any random executable). You should be able to launch apps from a RNW module via LaunchUriAsync and other WinRT apis that do work in an app container, see https://docs.microsoft.com/en-us/windows/uwp/launch-resume/launch-app-with-uri