We are happily running unicorn in VS2015 with Sitecore 8.2, but we need to bring in some items from a Sitecore 7.2 instance. Unfortunately I cannot get Unicorn to install via NuGet. Every time I try, it errors out on Rainbow with this message:

Install-Package : Could not install package 'Rainbow.Core 1.4.1'. You are trying to install this package into a project that targets '.NETFramework,Version=v4.5.1', but the package does not contain any assembly references or content files that are compatible with that framework.

I don't see anywhere that a particular .NET framework version is required. SC82 is running on 4.6.1, but I don't think I can do that for SC72.

I've also tried installing Rainbow by itself first, which attempts to install 1.4.2, but that fails with the same error.

Lastly, I tried adding the NuGet package with a new Visual Studio 2015 project created by the SIM tool and it errors out with the same message (except it is using .NET 4.5)

Anything I can try?

closed as off-topic by Mark Cassidy May 1 '17 at 10:30

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Looking at the assembly in ILSpy, you need 4.5.2.

[assembly: TargetFramework(".NETFramework,Version=v4.5.2", FrameworkDisplayName = ".NET Framework 4.5.2")]


Updating my project TargetFrameworkVersion to 4.5.2 allowed me to install Rainbow and therefore the Unicorn nuget packages. So the issue was that I had my TargetFrameworkVersion set too low (4.5 or 4.5.1). Looking at the source on github allowed me to see that the TargetFrameworkVersion listed in https://github.com/kamsar/Rainbow/blob/master/src/Rainbow/Rainbow.csproj was newer than what I was using.

  • Make sure that your promotion environment dev/test has the same patch level of .Net as well. .Net 4.5.X is in-place upgrade. – Roman Apr 29 '17 at 2:18

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