MVVM Light assembly conflict with Microsoft.Practices.ServiceLocation - mvvm-light

Question

I've got an issue where my WPF application cannot be published with ClickOnce.
The application uses Nuget packages MVVM Light 4.1.26.1, Unity 2.1.505.2, CommonServiceLocator 1.0.
The problem is that when I publish, it all build fine, but I get this error when I try and install the clickonce package:
Unable to install or run the application. The application requires that assembly Microsoft.Practices.ServiceLocation Version 1.0.0.0 be installed into the Global Assembly Cache (GAC) first.
I did some digging and saw that there were two references to that assembly in the manifest, and one of them was marked as a prerequisite which I can't get rid of:
<dependency>
<dependentAssembly dependencyType="preRequisite" allowDelayedBinding="true">
<assemblyIdentity name="Microsoft.Practices.ServiceLocation" version="1.0.0.0" publicKeyToken="59D6D24383174AC4" language="neutral" processorArchitecture="msil" />
</dependentAssembly>
</dependency>
<dependency>
<dependentAssembly dependencyType="install" allowDelayedBinding="true" codebase="Microsoft.Practices.ServiceLocation.dll" size="29760">
<assemblyIdentity name="Microsoft.Practices.ServiceLocation" version="1.0.0.0" publicKeyToken="31BF3856AD364E35" language="neutral" processorArchitecture="msil" />
<hash>
<dsig:Transforms>
<dsig:Transform Algorithm="urn:schemas-microsoft-com:HashTransforms.Identity" />
</dsig:Transforms>
<dsig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha256" />
<dsig:DigestValue>eee+a+dQmhpSY/ApLxRipXdEp8UsTaZHXHClBU0Iwyc=</dsig:DigestValue>
</hash>
</dependentAssembly>
</dependency>
I'm pretty sure the issue with the ClickOnce is down to there being two references to this assembly with the same version (but notice the different public key tokens).
I created a very simple repro as follows:
Create a new WPF application
Add Nuget package MVVM Light
Add Nuget package Unity (also adds dependant package called
CommonServiceLocator)
Build and publish the WPF application
Try and install the published MyApp.application clickOnce package....get the error detailed above
Here's a repro project:
skydrive repro project
Any ideas how I might get over this?

Answer 1

It's now 2019 and I ran into a similar problem, found this question as first entry, but found another (more recent) problem and solution to get MVVMLight and Microsoft.Practices.ServiceLocation work together.
Mvvmlight 5.4.1.1 doesn't work with CommonServiceLocater 2.0.4 (which is both the lastest stable build in March 2019) the way mvvmlight bootstraps it's ViewModelLocator.cs
Two things worked:
either downgrading to
CommonServiceLocater 1.3.0
Mvvmlight 5.3.0.0
or changing the reference from
using Microsoft.Practices.ServiceLocation;
to
using CommonServiceLocator;

Answer 2

Please try again. I just pushed a new build (4.1.27.0) to Nuget that is depending on the official CommonServiceLocator package where available. This should fix your issue. If you have more problems, please make sure to let me know.
Cheers
Laurent

Answer 3

Yes. The MVVMLight ServiceLocation assembly uses a different public key token than every other public implementation. It has made my life a nightmare for quite some time. I finally had to rip out all my nuget assemblies and go back to file references in a common directory for now. I am waiting for Laurent to fix this.

Answer 4

I had this problem as well despite having the 4.1.27 build of the MVVMLight nuget package installed. After hours of frustration I figured out it was because I had the MVVMLight toolkit (v.4.1 for Visual Studio 2012) installed. Once I uninstalled it, my deployment started working again.
Just thought I'd leave this here in case anyone else runs into that particular scenario.