Application can't scaffold items
In my case I moved my connection strings out of the Web.config to
<connectionStrings configSource="ConnectionStrings.config"/>
that when I started getting the error when I was trying to scaffold.
There was an error running the selected code generator: ‘Exception has been thrown by the target of an invocation.’
Moving my connection strings back to the Web.config solved my issue.
I had this problem too, I solved the problem by calling the base.onModelCreating in my DB context
base.OnModelCreating(modelBuilder);