Can't authenticate using secWinAD protocol with .Net SDK

[#1]

I'm attempting to authenticate using a .Net client.

The relevant code:

ISessionMgr sessionMgr = CrystalEnterprise.GetSessionMgr();  
IEnterpriseSession enterpriseSession = sessionMgr.Logon([userName], [password], [server:6400], [authentication]);

If I use an account with secWinAD credentials, I get an error on the Logon line that reads:

System.ArgumentNullException: 'Value cannot be null.Parameter name: assembly'

If I use an account with secEnterprise credentials, however, the Logon method works.

I noticed that the secWinAD protocol isn't installed:

sessionMgr.InstalledAuthProgIds
{string[1]}
  [0]: "secEnterprise"

I've added the CrystalDecisions.Enterprise.Auth.secWinAD assembly to the project's reference.

When I use the RESTful SDK, I can access this server w/ the AD account.

What am I missing? Is there a way to programmatically add the secWinAD auth?

[first_last]

I appear to have the same version:

If it makes a difference, I can access the CMC and Launchpad using AD credentials.

[daniel_paulsen]

One thing that can cause strange behavior (everything works but .NET) is a mixture of assemblies in the Bin folder of the application.

This can happen if you've had "Copy Local : True" at any point and made changes to the application or runtime versions.

Old and incorrect versions can be left in the Bin folder after setting "Copy Local : False"

Try checking the application's Bin folder and remove any CrystalDecisions assemblies.

Dan