You cannot call a method on a null-valued expression.

[Chronosishere]

What's the problem?

Windows PowerShell
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PS C:\Windows\system32> cd c:\users\flare\desktop
PS C:\users\flare\desktop> (New-Object net.webclient).DownloadFile('https://raw.githubusercontent.com/mandiant/flare-vm/main/install.ps1',"$([Environment]::GetFolderPath("Desktop"))\install.ps1")
PS C:\users\flare\desktop> Unblock-File .\install.ps1
PS C:\users\flare\desktop> Set-ExecutionPolicy Unrestricted -Force
PS C:\users\flare\desktop> .\install.ps1
[+] Checking if PowerShell version is compatible...
[+] Installing with PowerShell version 5.1.19041.6093
[+] Checking if script is running as administrator...
[+] Running as administrator
[+] Checking if execution policy is unrestricted...
[+] Execution policy is unrestricted
[+] Checking Operating System version compatibility...
[+] Installing on Windows version
[+] Checking for spaces in the username...
[+] Username 'Flare' does not contain any spaces. [+] Checking if host has enough disk space... [+] Disk is larger than 60 GB [+] Checking for Internet connectivity (google.com)... [+] Internet connectivity check for google.com passed [+] Checking for Internet connectivity (github.com)... [+] Internet connectivity check for github.com passed
[+] Checking for Internet connectivity (raw.githubusercontent.com)...
[+] Internet connectivity check for raw.githubusercontent.com passed
[+] Network connectivity looks good
[+] Checking if Windows Defender Tamper Protection is disabled...
[+] Tamper Protection is disabled
[+] Checking if Windows Defender service is disabled...
[+] Defender is disabled
[+] Setting password to never expire to avoid that a password expiration blocks the installation...
[-] Have you taken a VM snapshot to ensure you can revert to pre-installation state? (Y/N): Y
[+] Getting user credentials ...

Windows PowerShell credential request
Enter your credentials.
Password for user Flare:

[+] Installing Boxstarter...
Welcome to the Boxstarter Module installer!
Chocolatey is going to be downloaded and installed on your machine. If you do not have the .NET Framework Version 4 or greater, that will also be downloaded and installed.
Forcing web requests to allow TLS v1.2 (Required for requests to Chocolatey.org)
Getting latest version of the Chocolatey package for download.
Not using proxy.
Getting Chocolatey from https://community.chocolatey.org/api/v2/package/chocolatey/2.5.0.
Downloading https://community.chocolatey.org/api/v2/package/chocolatey/2.5.0 to C:\Users\Flare\AppData\Local\Temp\chocolatey\chocoInstall\chocolatey.zip
Not using proxy.
Extracting C:\Users\Flare\AppData\Local\Temp\chocolatey\chocoInstall\chocolatey.zip to C:\Users\Flare\AppData\Local\Temp\chocolatey\chocoInstall
Installing Chocolatey on the local machine
WARNING: It's very likely you will need to close and reopen your shell
before you can use choco.
PATH environment variable does not have C:\ProgramData\chocolatey\bin in it. Adding...
WARNING: Not setting tab completion: Profile file does not exist at
'C:\Users\Flare\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1'.
Ensuring Chocolatey commands are on the path
Ensuring chocolatey.nupkg is in the lib folder
Chocolatey installed, Installing Boxstarter Modules.
Chocolatey v2.5.0
Installing the following packages:
Boxstarter
By installing, you accept licenses for the packages.
Downloading package from source 'https://community.chocolatey.org/api/v2/'
Progress: Downloading BoxStarter.Common 3.0.3... 100%

Boxstarter.Common v3.0.3 [Approved]
Boxstarter.Common package files install completed. Performing other installation steps.
Restricting write permissions of 'C:\ProgramData\Boxstarter' to Administrators
The Boxstarter.Common Module has been copied to C:\ProgramData\Boxstarter and added to your Module path.
You will need to open a new console for the path to be visible.
Use 'Get-Module Boxstarter.* -ListAvailable' to list all Boxstarter Modules.
To list all available Boxstarter Commands, use:
PS:>Import-Module Boxstarter.Common
PS:>Get-Command -Module Boxstarter.*

To find more info visit https://Boxstarter.org or use:
PS:>Import-Module Boxstarter.Common
PS:>Get-Help Boxstarter
Environment Vars (like PATH) have changed. Close/reopen your shell to
see the changes (or in powershell/cmd.exe just type refreshenv).
The install of Boxstarter.Common was successful.
Software install location not explicitly set, it could be in package or
default install location of installer.
Downloading package from source 'https://community.chocolatey.org/api/v2/'
Progress: Downloading BoxStarter.WinConfig 3.0.3... 100%

Boxstarter.WinConfig v3.0.3 [Approved]
Boxstarter.WinConfig package files install completed. Performing other installation steps.
Restricting write permissions of 'C:\ProgramData\Boxstarter' to Administrators
The Boxstarter.WinConfig Module has been copied to C:\ProgramData\Boxstarter and added to your Module path.
You will need to open a new console for the path to be visible.
Use 'Get-Module Boxstarter.* -ListAvailable' to list all Boxstarter Modules.
To list all available Boxstarter Commands, use:
PS:>Import-Module Boxstarter.WinConfig
PS:>Get-Command -Module Boxstarter.*

To find more info visit https://Boxstarter.org or use:
PS:>Import-Module Boxstarter.WinConfig
PS:>Get-Help Boxstarter
The install of Boxstarter.WinConfig was successful.
Software install location not explicitly set, it could be in package or
default install location of installer.
Downloading package from source 'https://community.chocolatey.org/api/v2/'
Progress: Downloading boxstarter.bootstrapper 3.0.3... 100%

Boxstarter.Bootstrapper v3.0.3 [Approved]
Boxstarter.Bootstrapper package files install completed. Performing other installation steps.
Restricting write permissions of 'C:\ProgramData\Boxstarter' to Administrators
The Boxstarter.Bootstrapper Module has been copied to C:\ProgramData\Boxstarter and added to your Module path.
You will need to open a new console for the path to be visible.
Use 'Get-Module Boxstarter.* -ListAvailable' to list all Boxstarter Modules.
To list all available Boxstarter Commands, use:
PS:>Import-Module Boxstarter.Bootstrapper
PS:>Get-Command -Module Boxstarter.*

To find more info visit https://Boxstarter.org or use:
PS:>Import-Module Boxstarter.Bootstrapper
PS:>Get-Help Boxstarter
The install of Boxstarter.Bootstrapper was successful.
Software install location not explicitly set, it could be in package or
default install location of installer.
Downloading package from source 'https://community.chocolatey.org/api/v2/'
Progress: Downloading boxstarter.chocolatey 3.0.3... 100%

Boxstarter.Chocolatey v3.0.3 [Approved]
Boxstarter.Chocolatey package files install completed. Performing other installation steps.
Restricting write permissions of 'C:\ProgramData\Boxstarter' to Administrators
The Boxstarter.Chocolatey Module has been copied to C:\ProgramData\Boxstarter and added to your Module path.
You will need to open a new console for the path to be visible.
Use 'Get-Module Boxstarter.* -ListAvailable' to list all Boxstarter Modules.
To list all available Boxstarter Commands, use:
PS:>Import-Module Boxstarter.Chocolatey
PS:>Get-Command -Module Boxstarter.*

To find more info visit https://Boxstarter.org or use:
PS:>Import-Module Boxstarter.Chocolatey
PS:>Get-Help Boxstarter
The install of Boxstarter.Chocolatey was successful.
Software install location not explicitly set, it could be in package or
default install location of installer.
Downloading package from source 'https://community.chocolatey.org/api/v2/'
Progress: Downloading Boxstarter.HyperV 3.0.3... 100%

Boxstarter.HyperV v3.0.3 [Approved]
Boxstarter.HyperV package files install completed. Performing other installation steps.
Restricting write permissions of 'C:\ProgramData\Boxstarter' to Administrators
The Boxstarter.HyperV Module has been copied to C:\ProgramData\Boxstarter and added to your Module path.
You will need to open a new console for the path to be visible.
Use 'Get-Module Boxstarter.* -ListAvailable' to list all Boxstarter Modules.
To list all available Boxstarter Commands, use:
PS:>Import-Module Boxstarter.HyperV
PS:>Get-Command -Module Boxstarter.*

To find more info visit https://Boxstarter.org or use:
PS:>Import-Module Boxstarter.HyperV
PS:>Get-Help Boxstarter
The install of Boxstarter.HyperV was successful.
Software install location not explicitly set, it could be in package or
default install location of installer.
Downloading package from source 'https://community.chocolatey.org/api/v2/'
Progress: Downloading boxstarter 3.0.3... 100%

Boxstarter v3.0.3 [Approved]
Boxstarter package files install completed. Performing other installation steps.
To load all Boxstarter Modules immediately, just enter 'BoxstarterShell'.
Interested in Windows Azure VM integration? Run CINST Boxstarter.Azure to install Boxstarter's Azure integration.
The install of Boxstarter was successful.
Software install location not explicitly set, it could be in package or
default install location of installer.

Chocolatey installed 6/6 packages.
See the log for details (C:\ProgramData\chocolatey\logs\chocolatey.log).

Installed:

• Boxstarter v3.0.3
• Boxstarter.Bootstrapper v3.0.3
• Boxstarter.Chocolatey v3.0.3
• Boxstarter.Common v3.0.3
• Boxstarter.HyperV v3.0.3
• Boxstarter.WinConfig v3.0.3
  Boxstarter Module Installer completed
  [+] Attempting to disable updates...
  Boxstarter: Microsoft Update is already disabled, no action will be taken.
  [!] Failed to disable Microsoft Store updates
  Chocolatey v2.5.0
  Added vm-packages - C:\Users\Flare\Desktop;.;https://www.myget.org/F/vm-packages/api/v2;https://myget.org/F/vm-packages/api/v2 (Priority 1)
  Chocolatey v2.5.0
  Enabled allowGlobalConfirmation
  Chocolatey v2.5.0
  Enabled allowEmptyChecksums
  Chocolatey v2.5.0
  Updated cacheLocation = C:\Users\Flare\AppData\Local\ChocoCache
  ForEach-Object : You cannot call a method on a null-valued expression.
  At C:\users\flare\desktop\install.ps1:518 char:37

•       $vm_packages.feed.entry | ForEach-Object {
  

•                                 ~~~~~~~~~~~~~~~~
  

  • CategoryInfo : InvalidOperation: (:) [ForEach-Object], RuntimeException
  • FullyQualifiedErrorId : InvokeMethodOnNull,Microsoft.PowerShell.Commands.ForEachObjectCommand

Steps to Reproduce

1. Just execute install.ps1

Environment

VirtualBox

Additional Information

No response

[Chronosishere]

Just half an hour ago I was able to complete this step and proceed with the installation of tools but got stuck during the installation on microsoft.office.development something and after going back to previous snapshot for another fresh installation of FlareVM, now it's stuck on this step and won't proceed.

[Fahd9944]

me to i have the same bug

[toh539py]

Adding to this. I am also experiencing this issue

[Ghostie-ctrl-z]

Same here its having issues with Updated cacheLocation

[Vkp-IT]

I am also unable to complete the installation.

[Darkcerbus]

Also getting this issue, anyone got an idea? Got a lab due Sunday LOL

[nitroz3us]

Temporary Workaround for ForEach-Object: You cannot call a method on a null-valued expression in install.ps1

Problem:
When running the FLARE VM installer, you may encounter this error:

ForEach-Object : You cannot call a method on a null-valued expression.
At C:\Users\Win10\Desktop\install.ps1:518 char:37
+           $vm_packages.feed.entry | ForEach-Object {
+                                     ~~~~~~~~~~~~~~~~

This happens if the downloaded vm-packages.xml is empty, malformed, or the API is unreachable, so $vm_packages.feed.entry is $null.

---

Temporary Solution / Workaround

In the Get-Packages-Categories function, replace:

$vm_packages.feed.entry | ForEach-Object {    
      # ... existing code ...
    }

With this improved check:

if ($vm_packages.feed.entry) {
    $vm_packages.feed.entry | ForEach-Object {
        # ... existing code ...
    }
} else {
    Write-Host "[!] No package entries found in the downloaded XML. The file may be empty, malformed, or the API is unreachable." -ForegroundColor Red
    # Optionally, print the file path or contents for debugging
}

---

Why this helps

• Prevents the script from crashing if the XML is empty or malformed.
• Gives a clear error message if the download failed or the API is down.
• Makes it easier to debug network or API issues.

---

Hope this helps!

[shravaka]

@nitroz3us I can see the function you mention, but I can't find the corresponding code. Are you sure this is correct?

[nitroz3us]

@shravaka I've opened a PR, you can take a look here. #710

[Ana06]

This seems related to #695.

Was MyGet down or what caused the XML file to be malformed? 🤔

[Ana06]

@nitroz3us I think the installation can likely not continue successfully if the XML is empty or malformed. Your PR is ignoring the issue, while I think we should likely display a better error instead (that is tracked in #695).

I can't reproduce the issue and I haven't experienced myself. Can someone that did encounter the issue confirm if this is still happening (then we need to investigate why it happens) or if this was just a punctual issue (likely because MyGet had issues and the installation was not possible anyway as we rely on it for the installation, just enhancing error messages would be needed which is tracked in #695)?