Hi, I was just trying out the API latest version 4.4.13. Tried out both IQFeed and IB connectors. IQ Feed works great, but IB has a bug where my account # starts with a letter and it looks like you are trying to convert it to a number. Take a look at the exception attached. This happens when I try to call portfolios.ForEach(Trader.RegisterPortfolio) right from your IB sample app in Mainwindow.xaml.cs. If I comment out that line, the rest of it works fine.