I found the answer in issues by Diego Koz.
It is probably a change in TopKPooling 13, now the function returns
return x, edge_index, edge_attr, batch, perm, score[perm]
So it needs to be added another  _  in the  forward  function. e.g.
x, edge_index, _, batch, _, _ = self.pool1(x, edge_index, None, batch)
instead of
x, edge_index, _, batch, _ = self.pool1(x, edge_index, None, batch)