指定された名前付きパラメーターを使用してパラメーターセットを解決することはできません

以下のスクリプトでは、-liveまたは-testパラメーターのいずれかが必要です。ただし、スクリプトはどちらのスイッチも使用せずに実行されます。これらのパラメータのいずれかを使用すると、以下のエラーが発生します。-liveまたは-testのいずれかを必要としないのはなぜですか？また、それらのいずれかを使用すると失敗するのはなぜですか？

C：\ Users \ Administrator \ Documents \ Disable-ADAccounts.ps1：指定された名前付きパラメーターを使用してパラメーターセットを解決できません。行：1文字：1+。。\ Disable-ADAccounts.ps1 -days 7 -all -live + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~ + CategoryInfo：InvalidArgument ：（ :) [Disable-ADAccounts.ps1]、ParameterBindingException + FullyQualifiedErrorId：AmbiguousParameterSet、Disable-ADAccounts.ps1

    [CmdletBinding()]
    param (
    [Parameter(Mandatory = $true, ParameterSetName = 'UsersOnly')]
    [Switch]
    $usersOnly,

    [Parameter(Mandatory = $true, ParameterSetName = 'ComputersOnly')]
    [Switch]
    $computersOnly,

    [Parameter(Mandatory = $true, ParameterSetName = 'All')]
    [Switch]
    $all,

    [Parameter(Mandatory=$true)]
    [string]
    $days,

    [switch]
    $console,

    [Parameter(Mandatory = $true, ParameterSetName = 'Test')]
    [switch]
    $test,

    [Parameter(Mandatory = $true, ParameterSetName = 'Live')]
    [switch]
    $live
)

Process {
    $DC = Get-ADDomainController
    $OUs = Get-ADOrganizationalUnit -Filter * # Uncomment this line to search ALL OUs.  Comment Next Variable.
    #$OUs = Get-ADOrganizationalUnit -Filter 'Name -eq "test"' # Use this line to test on a single OU
    $TimeStamp = get-date -format D
    $description = "Disabled on " + $TimeStamp
    $noDisableComputer =  Get-ADGroupMember -Identity DoNotDisableComputers -Recursive | Select -ExpandProperty Name
    $noDisableUser =  Get-ADGroupMember -Identity DoNotDisableUsers -Recursive | Select -ExpandProperty Name
    $noDisable = $noDisableComputer+$noDisableUser
    $CurrentDate = Get-Date
    $CurrentDate = $CurrentDate.ToString('yyMMdd_hhmmss')
    $tempDir = [System.Environment]::GetEnvironmentVariable('TEMP','Machine')
    $logFile = $tempDir + "\DisabledAccounts_$CurrentDate.csv"

    # If -test switch is used enable -WhatIf parameter.
    If($test) { $whatIf = @{ WhatIf = $true } }
    ElseIf($live) { $whatIf = @{ WhatIf = $false } }

    # Set parameter to UsersOnly, ComputersOnly, or do not use a perameter
    If($usersOnly) { $scope = @{ UsersOnly = $true } }
    ElseIf($computersOnly) { $scope = @{ ComputersOnly =$true } }
    ElseIf($all) { $scope = @{} }

    # Disable User and/or Computer Objects inactive for XX days.

    # Iterate through Organizational Units
    foreach ($OU in $OUs) {

        # Search for User and/or Computer Objects inactive for XX days.  Disable object if not in DoNotDisable Security Groups
        $days = $days + "D"
        $accounts = Search-ADAccount -SearchBase $OU.DistinguishedName -SearchScope OneLevel -AccountInactive -TimeSpan ([timespan]7D) @scope
        foreach($account in $accounts){
            If ($noDisable -notcontains $account.Name) {
                Write-Host $account
        #        #Disable-ADAccount -Identity $account.DistinguishedName -Verbose $whatIf | Export-Csv $logFile
           }
        }
    }
}    

        # Move Disabled Users to Disabled Users OU & Add Timestamp to Description
        #Search-ADAccount –AccountDisabled –ComputersOnly –SearchBase $OU.DistinguishedName | Foreach-object {
            #Set-ADComputer $_ -Description $description -Verbose -WhatIf
            #Move-ADObject $_ –TargetPath “OU=Disabled Computers, DC=COH,DC=net” -Verbose -WhatIf
        #}
    #}