Can you post the model number please.
Also are the lights just lit or are they flashing?
Ok is this just a freezer only?
How many dials are there at the top? Is there 1 or 2?
Ok thats great.
What you need to do is turn that dial anticlockwise to off position.
Wait a few seconds for the lights to go off then turn it back on and this will reset the flashing lights from there.
Then see how it goes from there. Fingers crossed its a one off and will be fine but if the lights start flashing again a few hours later then its picking up a fault in there.
Its more then likely too much ice built up around the fan and drain channel. What you need to do is either remove the evaporator cover at the top inside the freezer and clear the ice from there.
Or the easy way is find somewere to put your food and then empty the freezer and turn it off for 24 hours and keep the freezer door open.
This will allow the ice to melt itself from the back in there.
Then turn it back on and reset the lights again if flashing and that will cure the fault from there for you.
See how it goes from there. Fingers crossed it just needed resetting but if it flashes again then you need to defrost it as the drain channel at the back inside the freezer will be blocked with all ice as we see this alot.
If you could remember to rate the answer as well that would be great. You can still get back to me on this even after rating so that isnt a problem.