I only get this error when I load the model with GPU:
use_cuda = torch.cuda.is_available()
device = torch.device("cuda:0" if use_cuda else "cpu")

model = ResNet3D().to(device)
model.apply(weights_init)

input = torch.rand([2,1,86,110,78])
output = model(input) 
print(input.shape)
print(output.shape)

Then comes the error: RuntimeError: No function is registered for schema aten::thnn_conv3d_forward(Tensor self, Tensor weight, int[3] kernel_size, Tensor? bias, int[3] stride, int[3] padding) -> (Tensor output, Tensor finput, Tensor fgrad_input) on tensor type CUDATensorId; available functions are CPUTensorId, VariableTensorId
if I load the model in cpu:
model = ResNet3D()
model.apply(weights_init)
output = model(input)
print(input.shape)
print(output.shape)

gives output nicely:
torch.Size([2, 1, 86, 110, 78])
torch.Size([2, 256])