Stale fuel is one of the most common causes of engines / lawn mowers to stop running or to run raggedly (hunting). This sort of issue can happen in all price brackets and is not something that is covered under the warranty for all manufacturers.
We mostly sees this sort of issue after the New Year where the lawnmower has been left in storage with fuel in the tank and will then refuse to start due to the carb being ‘gummed up’.
Luckily there is a possible way to fix this.
Hopefully when you restart the machine this will have sorted the problem for you. Unfortunately if this has not rectified the issue, it will need to be taken to a local dealer for inspection/repair, please bear in mind that if it is a fuel related issue it may not covered under the warranty.
To maintain the fuel, we would suggest purchasing a fuel stabiliser as this will keep the fuel fresher for a longer duration of time. The directions of use will be on the bottle but normally you can use a 10ml of stabiliser for 10L of fuel for occasional use or 10ml for 3L for long term storage.