System.InvalidCastException in GetSharedMailbox of Redemption

I am trying to get the email account associated with some shared mailbox whose email is sent as a parameter. The followed code works fine when I execute it on Outlook 2013. However, it throws a System.InvalidCastException on Outlook 2016.

public string GetUserSMTPAddressOfSharedMailbox(string email)
{
    Redemption.IRDOStore store = RdoSession.GetSharedMailbox(email);
    if(store != null && store.StoreAccount != null)
    {
          return store.StoreAccount.CurrentUser.SMTPAddress;
    }

    return null;
}


System.InvalidCastException: Unable to cast 
    COM object of type 'System.__ComObject' to interface type 
    'Redemption.IRDOSession'. This operation failed because the 
    QueryInterface call on the COM component for the interface with IID 
    '{E54C5168-AA8C-405F-9C14-A4037302BD9D}' failed due to the following 
    error: No such interface 
    supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).
at System.StubHelpers.StubHelpers.GetCOMIPFromRCW(Object objSrc, IntPtr 
    pCPCMD, IntPtr& ppTarget, Boolean& pfNeedsRelease)
at Redemption.IRDOSession.GetSharedMailbox(Object NameOrAddressOrObject)