Voltage-Source with OP

Yes and No, we know at which stage of simulation EC fails. Its the so called DC OP stage, which is the first thing a simulator does before it can start with a transient analysis. All tricks to avoid this problem are related to take out the OpAmp while DC OP is done. Take it out means its in dark grey highlighted to be not present. This can be done with switches or a relay at startup. Anothet methode is to cut both DC pathes to the OpAmp inputs with capacitors. Because the inputs do have infinite high impedance they dont hurt when transient mode does take over, but while DC OP the OpAmp is taken out from simulation. http://everycircuit.com/circuit/6087687271088128

Another anomaly that I noticed is that your circuit needs capacitors in series to the op amp (as hurz demonstrated), but my circuit (with a MOSFET as the pass transistor) needs capacitors in parallel to the op amp inputs to work http://everycircuit.com/circuit/5578554310656000

Putting the caps in mine in series makes the app crash, irrespective of the state of the switch

@PrathikP, you noticed you circuit is a different one, with a P-channel Mosfet you need the inverse logic to this circuit. The crashes are also different, while here we have CFS in you circuit at least on scenario is a convergence problem which cuz freezing while CFS is different without any hope of convergence. I dont think it helps here to understand why here series capacitors help and in your different circuit it seemse to not help at all. Better you open an parallel thread to have a separate discussion on this topic.

I don't really understand the problem very well. I just mentioned it cause I faced a similar issue.