How to fix service code i30 AEG F88080IA?

AEG F88080IA service error i30.

This happened a number of times- there is no leak but the flood protection is activating usually last 4-5 minutes of the programme usually during the hot rinse.
I wouldn't mind to call technician for proper service, however it is located in Bulgaria where
Engineers DO NOT go to addresses - I have to take it on my own to the service for repairing.
The first time it happened I did so and they couldn't find any fault and it has been returned.
Last time after reading other people reviews, I tried to move and slightly shake it, it worked.

Now it works fine until last 5 minutes of the programme when Service code i30 message appears and starts beeping.

Any advice will be highly appreciated.