Multisim does not simulate the capacitor charge correctly
It only works fine in the simulator because with a phase angle of 0&deg; it starts at 0 V. In reality when you switch on the mains it could be at any point in the waveform. Change the phase angle to 90&deg; or 270&deg; to see what would happen if it was switched on at peak voltage, and then you will know why your LEDs die.

But even if you could somehow ensure that your circuit was only switched on during zero crossings, operating it without series resistance is a bad idea. At 50 Hz the capacitor has sufficient impedance to limit the current, but at higher frequencies it doesn't. AC mains often has higher frequencies impressed on it due to inductive devices such as motors and transformers being switched on and off, 'ripple' control signals etc. The LEDs might survive a few spikes but will eventually die.