Failed to instantiate manager instance

Question

I am using this library to develop a asp.net web api for MetaTrader4, but failed to instantiate. Here is My trial:

[Route("users/")]
public IList<UserRecord> GetAllUsers()
{
    IList<UserRecord> users;
    using (var metatrader = new ClrWrapper(new ConnectionParameters
    {
        Login = 123456,
        Password = "managerPassword",
        Server = "123.123.123.123:443"
    }))
    {
        users = metatrader.UsersRequest();
    }
    return users;
}

And the Exception is:

Failed to instantiate manager instance
於 P23.MetaTrader4.Manager.ClrWrapper..ctor(String metatraderLibraryPath) 於 P23.MetaTrader4.Manager.ClrWrapper..ctor(ConnectionParameters connectionParameters, String metatraderLibraryPath) 於 P23.MetaTrader4.Manager.ClrWrapper..ctor(ConnectionParameters connectionParameters) 於 mt4_api.Controllers.UsersController.GetAllUsers() 於

The Code is Ok when it runs under console project, but fail in asp.net web api project.

Can Someone helps?