I've just installed the latest beta and tried to connect through my local TWS instance to get the E-Mini S&P 500 (ESZ6) and I'm experiencing the same problems other people reported in the last few days.
I add a contract but it's nowhere to be found on the QM or when I try to create a chart.
So I guess this means the bug is real...

If there's any workaround to be made I'll be happy to try it out.