"Error in parsing the app package." when opening Windows 10 .appinstaller file from web (MSIX)

Question

So I'm trying to use the direct app install feature of Windows 10 Creators Update to allow downloading a packaged modern app from the web. The key feature of it is that it will auto update your app by checking back to the same URL of the .appinstaller file.

https://new-file-explorer.firebaseapp.com/ (the page is entirely generated by Visual Studio, no modifications from me)

The problem is that when I click it I just get "Error in parsing the app package."

If I manually download the .msixbundle that's referenced in the .appinstaller file it will work! Yet App Installer itself can't "parse" this package?

Here's the weirdest part: if I use "Add-AppxPackage -Appinstaller" from Powershell and point it towards the .appinstaller URL it will completely work!

The other answers on here do not apply, since they were all related to running it on a local server (I tried it anyways).

I thought this was related to MIME types, but I have set the MIME types as stated in the documentation and yet it still doesn't work. I've verified that by using this URL MIME type checker. I'm at a loss to what is actually causing this.

Here is the .appinstaller file:

<?xml version="1.0" encoding="utf-8"?>
<AppInstaller Uri="https://new-file-explorer.firebaseapp.com/InstallNFE.appinstaller" Version="1.0.9.0" xmlns="http://schemas.microsoft.com/appx/appinstaller/2017/2">
  <MainBundle Name="NewFileExplorer" Version="1.0.9.0" Publisher="CN=david" Uri="https://new-file-explorer.firebaseapp.com/InstallNFE_1.0.9.0_Test/InstallNFE_1.0.9.0_x86_x64.msixbundle" />
  <UpdateSettings>
    <OnLaunch HoursBetweenUpdateChecks="0" />
  </UpdateSettings>
</AppInstaller>

Here's a link to the .msixbundle it appears to be incapable of parsing (as you can see, it works manually downloading it!)

Answer 1

Thought of putting the solution in case someone else is facing the issue. I also faced the same issue and was able to resolve myself. When opening the Windows 10 .appinstaller file from web, the error "Error in parsing the app package." occurs.

For me the cause was that the links provided in the HTML page index.html generated by Visual Studio was referring to some share location (as my installer location was a file share location) and the installer file was not there. The reason for this is that I didn't do the last step "Copy and Close" of publishing from VS (this step copies the installer from output location to installer location that you provided). Instead of "Copy and Close", I just clicked on another option "Close" and hence the issue.