Why is my TWS flashing a magenta grid, then trying to log back in again?

You must select live or paper trading mode prior to logging in. You cannot switch modes once you have logged in.

It is very easy to switch from live trading to paper (simulated) trading and back again whether you are using Trader Workstation (TWS), IBKR Mobile, Client Portal or IBKR Desktop. Open the Login box, and:…

If you have received confirmation that your account application has been approved but you are not able to log in to any of the trading platforms, your access to the trading platform is likely restricted due to one of the following conditions:

1. Your account application has been approved by less than 24 hours. Note that you will have to wait 24 hours before trading access is enabled once the account has been approved…

A given username can only have one session active at a given time. However the session handoff is supported by all IBKR trading platforms. If you have a trading session running on a specific device (e.g. your Desktop computer) and you start another trading session on a different device (e.g. your smartphone), you will be prompted, upon login, to terminate the previous session or cancel the current login attempt.  If you elect to terminate the previous session, your Desktop platform will disconnect, allowing you to complete the login on your mobile device. Moreover, you can as well transfer your account authentication over to the IBKR Mobile app, which saves you the effort of opening and logging in to IBKR Mobile…

Yes, you can have both trading apps downloaded to the same computer, and you can log into either one at any time.  Additionally, you can trade your account from any of our trading apps including Client Portal, IBKR Mobile, TWS and IBKR Desktop using the same login credentials. The only limitation is that you can only be logged into one platform at a time. You must log out of one platform before you will be able to log into the other. …