Cannot run scikit-image in Python 3.6

[snippsat]

You should only have one Anaconda instantiation.
If it work in some scenarios dos not mean that it work in all(should not jump at all).
It easy to create isolated virtual environment,so no need for two main installation.
Example:

# Make enviroment
G:\Anaconda3\Scripts
λ conda create -n sci_env scikit-image numpy    

# Activate
G:\Anaconda3\Scripts
λ activate sci_env

(sci_env) G:\Anaconda3\Scripts
λ which python
/g/Anaconda3/envs/sci_env/python

# Run your first code added print(histo)
(sci_env) G:\Anaconda3\envs\sci_env
λ python sci_test.py

Output:
(array([   0,    1,    2,    7,   10,    7,   10,   27,   16,   14,   17,
         .......................................
       247, 248, 249, 250, 251, 252, 253, 254, 255]))

So working and totally isolated from main version.
You can look at my tutorial about Anaconda