ImportError: IProgress not found. Please update jupyter and ipywidgets although it is installed

I tried everything you mentioned in a new environment using conda and I had another issue related to the version of ipywidgets (a bug found in Github with comments saying that got solved after using last version). I solved the problem I had installing last version of ipywidgets. Here is my process:

1. Create a new environment using conda (I use miniconda):

conda create --name teststackoverflow python=3.7

2. Activate new environment:

conda activate teststackoverflow

3. Install jupyter:

pip install jupyter

4. Install all the libraries without specific versions to get the last ones:

pip install ipywidgets widgetsnbextension pandas-profiling

5. Run jupyter notebook in the console to turn on the notebooks server and create a new notebook.
6. Run this line in a new cell:

!jupyter nbextension enable --py widgetsnbextension

With the result:

Enabling notebook extension jupyter-js-widgets/extension...
      - Validating: OK

7. Run some sample code to define df:

import pandas as pd
df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [1, 2, 3, 4]})

8. Run the code you provided:

from pandas_profiling import ProfileReport
profile = ProfileReport(df, title="Pandas Profiling Report", explorative=True)
profile.to_widgets()

Final output looks good: