Hi all. I am hitting at the above error while training the below model. Can any one explain me what exactly the error means  and how to resolve it ?

class CNN_Text(nn.Module):
def __init__(self):

    super(CNN_Text, self).__init__()
    V = 17419
    D =  300
    C = 4
    Ci = 1
    Co  = 100
    Ks = [3,4,5]
    self.dropout = 0.5
    self.embed = nn.Embedding(V, D)
    print self.embed.shape
    self.convs1 = nn.ModuleList([nn.Conv2d(Ci, Co, (K, D)) for K in Ks])
    self.dropout = nn.Dropout(self.dropout)
    self.fc1 = nn.Linear(len(Ks) * Co, C)

def conv_and_pool(self, x, conv):
    x = F.relu(conv(x)).squeeze(3)  # (N,Co,W)
    x = F.max_pool1d(x, x.size(2)).squeeze(2)
    return x

def forward(self, x):
    x = self.embed(x)  # (N,W,D)

    #if self.static:
    #x = Variable(x)+
    x = x.unsqueeze(1)  # (N,Ci,W,D)
    x = [F.relu(conv(x)).squeeze(3) for conv in self.convs1]  # [(N,Co,W), ...]*len(Ks)
    x = [F.max_pool1d(i, i.size(2)).squeeze(2) for i in x]  # [(N,Co), ...]*len(Ks)
    x = torch.cat(x, 1)
    x = self.dropout(x)  # (N,len(Ks)*Co)
    logit = self.fc1(x)  # (N,C)
    return logit