Late-bound call on Nothing: NullReferenceException or COM dispatch?

Direct answer

In standard VB.NET with Option Strict Off, a late-bound member call on a Nothing reference raises a managed NullReferenceException before the binder attempts any dispatch. The runtime binder checks the target for null first; it does not forward a Nothing target to COM dispatch. This is the expected behavior for ordinary .NET objects on .NET Framework and .NET 6+.

Confirmed facts and likely explanation

Confirmed: Option Strict On rejects late-bound calls at compile time, so the ambiguity appears only with Option Strict Off. Confirmed: a null target cannot expose members, so the managed null exception is the expected result for plain .NET objects.

Likely explanation for COM-dispatch reports: the variable may hold a COM Runtime Callable Wrapper or a COM object reference rather than a true managed Nothing. In that case the binder can reach COM activation and surface a dispatch error. That is a separate case from a managed Nothing reference.

Verification steps

1. Confirm Option Strict Off is enabled in the project or file.
2. Run this minimal reproduction:

Option Strict Off

Module Module1
    Sub Main()
        Dim target As Object = Nothing
        Console.WriteLine(target.ToString())
    End Sub
End Module

Observe the exception type. A NullReferenceException means the managed null check ran first. A COM or dispatch error suggests the target was a COM wrapper, not a plain Nothing.

Build and run with the .NET SDK:

dotnet build
dotnet run

Assumptions and uncertainty

• Assumes the Microsoft.VisualBasic runtime binder on .NET Framework or .NET 6+.
• Does not cover VBA, where the host raises its own "object variable not set" error and COM semantics differ.
• Unverified: behavior when Nothing is assigned to a variable typed as a COM class or when an RCW is involved. Treat COM-dispatch reports as requiring a separate reproduction.

Missing diagnostic detail

Was the Nothing variable ever assigned a COM object or RCW? That detail determines whether COM dispatch is in scope.