Breaking PowerShell since ... *muffled sounds*

Breaking.Types.ps1xml

<!-- This breaks ConvertTo-JSON for strings -->
<Types>
    <Type>
        <Name>System.String</Name>
        <Members>
            <ScriptProperty>
                <Name>AsBase64</Name>
                <GetScriptBlock>
                    [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($this))
                </GetScriptBlock>
            </ScriptProperty>
            <ScriptProperty>
                <Name>FromBase64</Name>
                <GetScriptBlock>
                    [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($this))
                </GetScriptBlock>
            </ScriptProperty>
        </Members>
    </Type>
</Types>

Working.Types.ps1xml

<Types>
    <Type>
        <!-- This gives me the Base64 functionality, without breaking ConvertTo-JSON -->
        <Name>System.String</Name>
        <Members>
            <ScriptMethod>
                <Name>ToBase64</Name>
                <Script>
                    [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($this))
                </Script>
            </ScriptMethod>
            <ScriptMethod>
                <Name>FromBase64</Name>
                <Script>
                    [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($this))
                </Script>
            </ScriptMethod>
        </Members>
    </Type>
</Types