OWIN-MixedAuth | Mixed Authentication for OWIN | Authentication library

I have a project where Windows Authentication and Forms login are required. I came across OWIN Mixed Authentication which seems to meet my requirements.

Before implementing into my own project I tried running the sample solution from the source link.

I debugged the solution using IIS Express and when I entered my credentials into the windows authentication dialog my correct credentials where found in the logonUserIdentity variable.

But when I set up a local IIS site add set the following feature delegation property as stated in the readme file:

I'm using Oracle DB, Entity Framework, Microsoft ASP.NET Identity, OWIN, and OWIN-MixedAuth.

Inside the execution of UserManager.FindByName(name), I'm getting: "EntityCommandExecutionException: An error occurred while executing the command definition." The internal exception is OracleException: ORA-00904: "Extent1"."USERNAME1": invalid identifier."

It is entirely true that I don't have a column named "USERNAME1" in the database, and it makes sense that the Identity framework can't find that column. The trouble is: I don't know why it's looking for that column to begin with. The IdentityUser.UserName is mapped explicitly in the DbContext like so:

modelBuilder.Entity().Property(r => r.UserName).HasColumnName("USERNAME");

I searched my code for "USERNAME1" just in case I had an ill-defined magic string somewhere, but there are no results found in my code. I've searched for this error, but it seems like I'm the only one getting this kind of error from inside the framework.

Can anyone think of anyplace where its getting this column name and how I can correct it?

Thanks in advance.