Adding ServiceStack reference breaks extension methods

Whenever we install ServiceStack 3.9.x on a new v7 install we get the error message:

‘umbraco.MacroEngines.DynamicNodeList’ does not contain a definition for ‘Any’

Removing ServiceStack.dll resolves the issue.

Does anyone know why or how we can work around it?


This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/55558-adding-servicestack-reference-breaks-extension-methods