WIX Installer: Updating existing value in config file - wix

Question

I am new to Wix and up till now I was able to manage it but now I want to update existing value of a Sub node from a config file. Below is my code to update it. But I get the error: failed to find the node.
<Component Id="ServiceIPAndPortSave" Guid="*" Directory="INSTALLFOLDER">
<CreateFolder/>
<util:XmlConfig
Id="UpdateIP"
On="install"
File="[INSTALLFOLDER]ProjectName.exe.config"
Action="create"
Node="value"
ElementPath="//configuration/userSettings/ProjectName.My.MySettings/setting[\[]#name='IPAddres'[\]]/#value"
Value="[SERVICEIP]"
/>
</Component>
And below is the format for my config file:
<configuration>
<userSettings>
<ProjectName.My.Settings>
<setting name="IPAddres" serializeAs="String">
<value>127.0.0.1</value>
</setting>
</ProjectName.My.Settings>
</userSettings>
</configuration>

Answer 1

Your XPATH expression is incorrect, you have two problems:
Your reference to the ProjectName.My.Settings element is invalid, you are using ProjectName.My.MySettings.
Your reference to the value element is invalid, you are using attribute notation.
And while not incorrect, you are rooting the search from anywhere by using // at the start of your query.
Try:
/configuration/userSettings/ProjectName.My.Settings/setting[\[]#name='IPAddres'[\]]/value