The right panel 'Simulation' tab for all parts in my design is empty, but sometimes (I think after restarting my browser, a refresh doesn't help) it populated. This extends to the graphs/readout on the canvas next to the components. Current project contains 2 SPST buttons, 4 NAND gates, 2 LEDs and a power source. This is also associated with the simulator being painfully slow. Sometimes it works fine though.