Invoking `z` drops my custom prompt about zlocation HOT 7 CLOSED

PS>& $Function:prompt
The property 'ErrorCount' cannot be found on this object. Verify that the property exists and can be set.
At line:4 char:9
+         $sl.ErrorCount = $global:error.Count
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : PropertyNotFound

Test-IsVanillaWindow : The term 'Test-IsVanillaWindow' is not recognized as the name of a cmdlet, function, script file, or operable
program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:7 char:12
+         if(Test-IsVanillaWindow) {
+            ~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Test-IsVanillaWindow:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Reset-CursorPosition : The term 'Reset-CursorPosition' is not recognized as the name of a cmdlet, function, script file, or operable
program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:13 char:9
+         Reset-CursorPosition
+         ~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Reset-CursorPosition:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Write-Theme : The term 'Write-Theme' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the
spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:14 char:9
+         Write-Theme -lastCommandFailed $lastCommandFailed
+         ~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Write-Theme:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Get-Command prompt | % Definition

        $lastCommandFailed = $global:error.Count -gt $sl.ErrorCount
        $sl.ErrorCount = $global:error.Count

        #Start the vanilla posh-git when in a vanilla window, else: go nuts
        if(Test-IsVanillaWindow) {
            Write-Host -Object ($pwd.ProviderPath) -NoNewline
            Write-VcsStatus
            return '> '
        }

        Reset-CursorPosition
        Write-Theme -lastCommandFailed $lastCommandFailed
        return ' '

Update-ZLocation $pwd

        $lastCommandFailed = $global:error.Count -gt $sl.ErrorCount
        $sl.ErrorCount = $global:error.Count

        #Start the vanilla posh-git when in a vanilla window, else: go nuts
        if(Test-IsVanillaWindow) {
            Write-Host -Object ($pwd.ProviderPath) -NoNewline
            Write-VcsStatus
            return '> '
        }

        Reset-CursorPosition
        Write-Theme -lastCommandFailed $lastCommandFailed
        return ' '

Update-ZLocation $pwd
ZLocationOrigPrompt