Some of the inner pipes may be frozen up.
The only way around this is to either thaw the entire fridge freezer for 24-48 hours, or try to locate the blockage and carefully thaw it out using a hairdryer or similar technique.
In most cases like this, I would recommend transferring the food to another fridge freezer and then turn it off and leave it to fully thaw out.
Very many thanks. After 4 days it suddenly decided to work without any help, but thank you all the same.
Glad to hear you got it sorted!
Have a great weekend :)Pete.