Welcome back to the community forum.
R Trader does not allow you to switch between live and sim within the platform. Rithmic actually uses two entirely different servers for their live and demo (paper trading) users, so you will need to establish which one you’d like to use on the initial login.
You can see the server differences below, demo or paper trading users must select the paper trading server when first logging in, while live users must select Rithmic 01:
As far as I know, yes, you can login to multiple instances of R Trader as long as they are different accounts! If you attempt to login with the same username you will automatically be kicked out. That being said, all of our live Rithmic users are eligible for a free Rithmic paper trading account upon request. So if you login with your live account on one instance and the paper trading account on the other one, you shouldn’t encounter any issues!
Thanks for your questions and let me know if you have anything else to ask about this topic!
Optimus Futures Support