MultiCharts: Trading Software for Automated Trading and Backtesting

Hi there, I am using Multicharts with Interactive Brokers. I always see yellow light and can not
connect to Interactive Brokers. I can connect yesterday, but can not connect today. May I have your suggestion which part might be wrong? Thanks!.
Charles

Please see my API setting as attached file,thanks!

Hello ctu1121,

It is recommended to add 127.0.0.1 to Trusted IP Addresses in IB TWS configuration.
If it is not added then TWS will prompt for connection confirmation each time. Most probably you have missed that popup window and have not allowed the connection.
Once you add it-restart MultiCharts. Please also make sure your IB broker profile is configured properly.