When I package my electron app for distribution using electron-builder I am getting the following error:

Error: his is not a published, standalone application and we are unable to locate the .NET Core SDK.  Please make sure that it is installed; see http://microsoft.com/net/core for more details.

I am using the same .NET code as the quickstart for a proof-of-concept.

Any ideas on why I'd get this error? I have confirmed the .dlls are getting copied into the package.