collision in wix extension: NetFxExtension - visual-studio

Question

I am trying to create a bootstrapper project in Visual Studio 2015 using Wix.
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"
xmlns:netfx="http://schemas.microsoft.com/wix/NetFxExtension"
xmlns:bal="http://schemas.microsoft.com/wix/BalExtension">
<Bundle Name="..." Version="1.0.0.0" Manufacturer="..." UpgradeCode="...">
<BootstrapperApplicationRef Id="WixStandardBootstrapperApplication.RtfLicense">
<bal:WixStandardBootstrapperApplication LicenseFile="mtel-eula-free.rtf"/>
</BootstrapperApplicationRef>
<BootstrapperApplicationRef Id="WixBootstrapperApplication:WixNetFxExtension" />
<BootstrapperApplicationRef Id="ManagedBootstrapperApplicationHost">
<Payload
Name="BootstrapperCore.config"
SourceFile="$(var.TargetDir)\BootstrapperCore.config"/>
<Payload
SourceFile="$(var.TargetPath)"/>
</BootstrapperApplicationRef>
<Chain>
<PackageGroupRef Id="NetFx45Web"/>
<MsiPackage Id="MTESetup" SourceFile="$(var.MTESetup.TargetPath)"/>
</Chain>
</Bundle>
</Wix>
The project name for the bootstrapper is MTEBootstrapper and the project name for the wix project for the MSI is MTESetup. For MTEBootstrapper, I added a reference to WixNetFxExtension.dll from Wix 3.10; In the properties of MTEBootstrapper, I added -ext WixNetFxExtension.dll. Now I am getting this error when I try to build MTEBootstrapper:
Error The extension 'Microsoft.Tools.WindowsInstallerXml.Extensions.NetFxExtension' contains a defintion for table 'NetFxNativeImage' that collides with a previously loaded table definition. Please remove one of the conflicting extensions or rename one of the tables to avoid the collision. MTEBootstrapper light.exe 0
I have no idea what is causing this. How do I fix it?

Answer 1

It looks like this error surfaces when I have both the reference to WixNetFxExtension added to MTEBootstrapper and the -ext option for the linker. I removed the -ext option for the linker and collision error disappeared.
(Separately I am getting an unresolved symbol WixNetFxExtension, which I will file a separate question for.)