WiXToolSet - Duplicate Symbol `Media:1` found - wix

Question

I'm new to WiX and am currently learning. It has quite the learning curve. I'm currently getting the error below:
Severity Code Description Project File Line Suppression State
Error Duplicate symbol 'Media:1' found. This typically means that an Id is duplicated. Check to make sure all your identifiers of a given type (File, Component, Feature) are unique. SetupProject1 \\Mac\Home\Desktop\myFolder\HelloWorld\SetupProject1\Product.wxs 12
I don't quite understand why I'm getting this error. If i change the Media Id="1" in the line <Media Id="1" Cabinet="simple.cab" EmbedCab="yes"/> to Media Id="2", the code seems to work. I don't understand because none of my other Id's have a 1 in them and yet I am still getting this error.
Also, if anyone happens to know what this line does: <Property Id="ADDINFOLDERFOUND" Value="NO" /> feel free to enlighten me, I didn't find anything in the docs about it.
Here is my code:
<?xml version="1.0" encoding="UTF-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
<?define HelloWorld_TargetDir=$(var.HelloWorld.TargetDir)?>
<Product Id="xxxxxxx-xxxx-xxxxx-xxxx-xxxxxxxxx"
Name="HelloWorldTestProject"
Language="1033" Version="1.0.0.0"
Manufacturer="testManufacturer"
UpgradeCode="xxxxxxx-xxxx-xxxxx-xxxx-xxxxxxxxx">
<Package InstallerVersion="200" Compressed="yes" InstallScope="perMachine" Comments="This is the commemnts section" />
<Media Id="1" Cabinet="simple.cab" EmbedCab="yes"/>
<MajorUpgrade DowngradeErrorMessage="A newer version of [ProductName] is already installed." Schedule="afterInstallInitialize" AllowSameVersionUpgrades="yes" />
<MediaTemplate />
<Property Id="ADDINFOLDERFOUND" Value="NO" />
<!--not sure what this line does-->
<Property Id="WIXUI_INSTALLDIR" Value="INSTALLFOLDER"/>
<UIRef Id="MyWixUI_InstallDir" />
<!--Add or remove programs properties-->
<!--Application Icon-->
<Icon Id="icon.ico" SourceFile="resources\SetupIcon.ico"/>
<Property Id="ARPPRODUCTICON" Value="icon.ico" />
<Directory Id="TARGETDIR" Name="SourceDir">
<!-- </Component> -->
<Component Id="HelloWorld.addin" Guid="xxxxxxx-xxxx-xxxxx-xxxx-xxxxxxxxx">
<File Id="HelloWorld.addin" Name="HelloWorld.addin" Source="$(var.HelloWorld_TargetDir)HelloWorld.addin" />
</Component>
<Component Id="HelloWorld.dll" Guid="xxxxxxx-xxxx-xxxxx-xxxx-xxxxxxxxx">
<File Id="HelloWorld.dll" Name="HelloWorld.dll" Source="$(var.HelloWorld_TargetDir)HelloWorld.dll" />
</Component>
</Directory>
<InstallExecuteSequence> <!-- Still working on figuring this out -->
</InstallExecuteSequence><!-- Still working on figuring this out -->
<InstallUISequence> <!-- Still working on figuring this out -->
</InstallUISequence> <!-- Still working on figuring this out -->
</Product>
</Wix>
Any help/direction is appreciated.

Answer 1

The MediaTemplate tag is redundant, remove it or comment it out and you should be good to go.
Property Id="ADDINFOLDERFOUND" Value="NO" is a custom property and from the code you posted, I don't see it being used.
See also: What is the difference between Media and MediaTemplate in WIX?
Hope this helps!