Help needed - 2011 Jimny violent knocking, shaking, engine cuts out and fuel

Thank you, that was the first mechanics first thought but fuel leak was ruled out there were no signs , as well as a choked catalytic converter, fuel filter. It happens when the engine is mid temp so not hot and not cold. It’s so strange. The first mechanic that came to rescue me spent 2 hours investigating all the possible problems that would come about from the symptoms and he said it was like they were all separate problems (which he checked) but it surely wouldn’t be possible for them all to happen at the exact same moment.

when you say mid temp.....do you mean the needle is at midway on gauge 
This is ideal temp for crank sensor to play up
I would look at getting a good second hand one to try
If you buy a new one don't buy a cheap one 

Yes, sorry I meant the needle is in the middle. Ok, I’ll look into a good second hand sensor and hope that will be it. Thank you so much.

it's located behind the alternator 
for now you could try spraying it with cold water like facade says

Are you 100% sure its not coils or plug wires? Make sure they are good ones if they have been replaced (you'll see why shortly).
I chased a misfire problem a couple years ago for weeks. Replaced coils, plugs, plug wires, still misfired badly under load. Started replacing sensors: cam, crank etc. with no luck. I took it to a mechanic around the corner from work and he could find nothing wrong either, even with his fancy scanner thingamy. checked over the fuel system, injectors etc all kinds of stuff. Eventually I gave up and took it into a reputable (but expensive) auto electrician/mechanic who specialises in diesel injection systems, asking him to check the fuel system for me properly. A few hours later he rang back and told me the brand new coils I put in a few weeks earlier were junk. They were a decent mid range aftermarket brand, (at least i thought so at the time) - VDO I believe the brand was. 
The mechanic even rang the parts store I got them from (Repco, a common chain store in NZ, a division of NAPA) and told them to give me my money back. 
​​​​​They swapped in a set of genuine coils and fixed the issue immediately.
It was misfiring and jerking and popping when you'd accelerate under load, along with a rich fuel smell as unburned fuel exited the tailpipe.
May not be your issue, but in hindsight would cost me half as much to just get genuine parts the first time round.
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Hi Hughes, the first mechanic took the plugs out and checked them all and considered they were in good condition as well as the coils. After checking there was no fuel leak, he checked for misfiring but to no avail. However, what I’ll do is when it goes back in the garage I’ll mention both suggestions I’ve got from here so far just to be extra sure!

Interestingly, I took it on a long trip at the weekend, and instead of using the E10 fuel, I used Vpower and added a shot of redex. It has been running really well. I wonder if I have two different issues that just happen to fail at the same time? Fuel management issues and the sensor?