Python anaconda conda issue: updating anaconda package impossible because processes are running

Question

I have an issue with updating anaconda's packages with conda. When I make a conda update --all, there is an issue which says to me:

Error: Unable to remove files for package: cryptography
Please close all processes running code from cryptography and try again.

However, none process are running, I have just the cmd window open. Same story when I want update dateutile for instance. It is like if conda uses some package and then I cannot update them? Somebody knows a method to close or remove those packages in order to reinstall them?

For information:

C:\Anaconda3\Scripts>conda info -a
Current conda install:
platform : win-64
conda version : 3.11.0
conda-build version : 1.11.0
python version : 3.4.3.final.0
requests version : 2.6.2
root environment : C:\Anaconda3 (writable)
default environment : C:\Anaconda3
envs directories : C:\Anaconda3\envs
package cache : C:\Anaconda3\pkgs
channel URLs : https://conda.binstar.org/juanlu001/win-64/
https://conda.binstar.org/juanlu001/noarch/
https://repo.continuum.io/pkgs/free/win-64/
https://repo.continuum.io/pkgs/free/noarch/
https://repo.continuum.io/pkgs/pro/win-64/
https://repo.continuum.io/pkgs/pro/noarch/
config file : C:\Users\maxime.condarc
is foreign system : False

Answer 1

This situation will be improved in the next version of conda, but for now, you can use conda install -f cryptography to force conda to update cryptography.