E2 or E9 on SMEG LS6000 Dishwasher

Have the above dishwasher, now intermittently going into fault modes, i.e., works properly 2 or 3 times then stops 5 mins into program & displays E2 or E9. On one occasion found black rubber flap in bottom of machine below filter & grille had become stuck in tube it covers, machine then worked properly once or twice before again showing fault. Flap not out of position every time it stops, water is lying in bottom of machine below grille, however. Any suggestions ??