The last disruption experiments in JET with plasma facing components (PFC) based on carbon-fibre composite tiles have been carried out using either Massive Gas Injection or a constant gas puff. These studies provided new data and increased the database on disruption generated runaway electrons (RE) at JET. Temporal and spatial dynamics of RE beams have been studied using inverse reconstruction of the measured hard and soft X-rays emission during RE plateaux. Energy of RE have been measured up to 15MeV. An analysis of plasma geometry spatial dynamics and RE generation at current quench (CQ) has shown that large decrease of RE generation rate could be achieved if plasma performs fast horizontal and/or vertical motions at CQ. Analysis of the experimental data and modelling of the interaction of RE beams with PFC in JET has shown that secondary RE could be generated during the interaction of the existing RE with PFC. First operations of JET with ITERlike Wall (ILW) have shown that the new all-metal environment did not favour to RE generation at disruptions.