1） ProtocolException: The remote server returned an unexpected response: (405) Method Not Allowed
The issue was, windows features for WCF was not enabled.
2） Login failed for user 'IIS APPPOOL\Classic .NET AppPool'
2.1） Are you using integrated security in the DB connection string? if so, you either need to change the connection string to specify a username or password. or change the asp.net settings in IIS to enable impersonation, this will mean the web app is running as another specified user (you would need to ensure the alternate user has access to the database otherwise you will have the same problem!)
2.2)
- Go into IIS Manager
- On the node with your computer name, select "Application Pools"
- Click "Classic .NET AppPool" and select "Advanced Settings..."
- Select "Identity" property and change its value to "LocalSystem"