My Visual Studio build is fine, but MSBuild (in VSTS in the cloud) fails:

Invalid TargetFSharpCoreVersion: ""; should be "", "" or "".

If I use command line MSBuild locally, this also fails.

I am using F# 4.1 (target F# runtime with WebSharper The issue is described here:

One of the replies says to edit WebSharper.targets, but of course, I don't want to do that.

Is this a problem with WebSharper 3 and F# 4.1? If so, how can I get MSBuild to work, like Visual Studio build does? I'm happy to avoid using F# 4.1 constructs within code marked as [<JavaScript>].