Upgrading from tensor rt 3 to 4

Every sample after compiling with make fails

./TensorRT-4.0.1.6/bin/sample_mnist
terminate called after throwing an instance of 'std::runtime_error'
  what():  Could not find mnist.prototxt in data directories:
	data/samples/mnist/
	data/mnist/
Annullato (core dump creato

Here is some other logs:

which tensorrt
which convert-to-uff
/usr/local/bin/convert-to-uff