@Mathieu, After further investigations, it appears when the pip installation is running that  tfdf is using a nightly version of KERAS ( keras-nightly 2.5.0.dev2021032900). I didn’t succeed in using keras==2.4.3 which gives also (as 2.4.1) good results for NN only…which is not the case with tf & Keras 2.5. Again, I’m afraid we can not use tfdf with Keras 2.4.3 ?