Fragment 元素包含未处理的扩展元素“util:RegistrySearch”

学习如何创建 Wix Booloader，以便我可以使用我的 msi 安装包安装 .NET Framework。无论如何，我遇到了未处理的扩展元素的错误。代码如下

<?xml version="1.0" encoding="utf-8"?>
<!--
# This comment is generated by WixEdit, the specific commandline
# arguments for the WiX Toolset are stored here.

candleArgs: "<projectfile>" -ext WixBalExtension
lightArgs: "<projectname>.wixobj" -ext WixBalExtension
-->
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi" 
 xmlns:util="http://schemas.microsoft.com/wix/UtilExtension">

<Bundle UpgradeCode="80B0ECBE-CAAE-4B6A-9705-49F0232B0C24" 
        Version="0.0.1">
    <BootstrapperApplicationRef Id="WixStandardBootstrapperApplication.RtfLicense" />
    <Chain>
        <PackageGroupRef Id="Netfx45" />
    </Chain>
</Bundle>

<Fragment>
    <util:RegistrySearch Root="HKLM" 
                         Key="SOFTWARE\Microsoft\Net Framework Setup\NDP\v4\Full" 
                         Value="Version" 
                         Variable="Netfx4FullVersion" />
    <util:RegistrySearch Root="HKLM" 
                         Key="SOFTWARE\Microsoft\Net Framework Setup\NDP\v4\Full" 
                         Value="Version" 
                         Variable="Netfx4x64FullVersion" 
                         Win64="yes" />
    <!-- .NET 4.5 only installed if Vista or higher AND it's not already installed-->
    <!-- .NET 4.5 only installed if Vista or higher AND it's not already installed-->    
<PackageGroup Id="Netfx45">
        <ExePackage Id="Netfx45" 
                    Cache="no" 
                    Compressed="yes" 
                    PerMachine="yes" 
                    Permanent="yes" 
                    Vital="yes" 
                    InstallCommand="/q" 
                    SourceFile="C:\Users\ProRip\Downloads\dotnetfx45_full_x86_x64.exe" 
                    DetectCondition="(Netfx4FullVersion=&quot;4.5.50709&quot;) AND (NOT VersionNT64 OR (Netfx4x64FullVersion=&quot;4.5.50709&quot;))" 
                    InstallCondition="(VersionNT &gt;= v6.0 OR VersionNT64 &gt;= v6.0) AND (NOT (Netfx4FullVersion=&quot;4.5.50709&quot; OR Netfx4x64FullVersion=&quot;4.5.50709&quot;))" />
    </PackageGroup>
</Fragment>

错误信息是

error CNDL0200 : The Fragment element contains an unhandled extension element 'util:RegistrySearch'.  Please ensure that the extension for elements in the 'http://schemas.microsoft.com/wix/UtilExtension' namespace has been provided.
error CNDL0200 : The Fragment element contains an unhandled extension element 'util:RegistrySearch'.  Please ensure that the extension for elements in the 'http://schemas.microsoft.com/wix/UtilExtension' namespace has been provided

任何人都可以解释我的错误是什么，我已经包含了正确的命名空间，但我看不到错误的原因！

命名空间的 WiX 扩展xmlns:util="http://schemas.microsoft.com/wix/UtilExtension由名为的 dll 提供WixUtilExtension（假设您使用的是 Visual Studio）。右键单击项目中的“引用”节点，然后添加对 WixUtilExtension dll 的引用。