Show(plot) on notebook does not produce any results

and in the console window I have the following messages:

Error: property Plot.center wasn’t declared

Any clues?
Thanks!

@ahassaine there is no way to speculate with so little information. Generally you should provide all relevant version information as well as a complete, minimal reproducing example.

Sorry, I cannot even run a basic example such as this one:

import numpy as np
from bokeh.io import curdoc, show
from bokeh.models import ColumnDataSource, Grid, LinearAxis, Plot, Rect
from bokeh.io import output_notebook
output_notebook()
N = 9
x = np.linspace(-2, 2, N)
y = x**2
w = x/15.0 + 0.3
h = y/20.0 + 0.3

source = ColumnDataSource(dict(x=x, y=y, w=w, h=h))

plot = Plot(
    title=None, plot_width=300, plot_height=300,
    min_border=0, toolbar_location=None)

glyph = Rect(x="x", y="y", width="w", height="h", angle=-0.7, fill_color="#cab2d6")
plot.add_glyph(source, glyph)

xaxis = LinearAxis()
plot.add_layout(xaxis, 'below')

yaxis = LinearAxis()
plot.add_layout(yaxis, 'left')
plot.add_layout(Grid(dimension=0, ticker=xaxis.ticker))
plot.add_layout(Grid(dimension=1, ticker=yaxis.ticker))
curdoc().add_root(plot)
show(plot)

Here are the versions:

BokehJS 0.13.0
Python 3.6.5

In the JS console, I also have the following output:

[bokeh] JS/Python version mismatch
[bokeh] Library versions: JS (0.13.0) / Python (2.0.2)

Please, let me know if there is anything else I can provide to help debug this?

Many thanks!

Perhaps worth adding that the issue seems to be related to display on notebook as saving to file using output_file continues to work as expected.

Well this is certainly the proximate reason:

The Bokeh Python and JS versions really need to match identically. Depending on you usage, it might be possible to vary by a point release or two. There is absolutely no chance whatsoever that output generated by Python Bokeh version 2.0.2 will be usable by BokehJS 0.13.

The real question is what is causing this mismatch because normally Bokeh handles loading the correct matching version of BokehJS itself. Is this an old notebook that you are trying to update? Maybe clear all the output cells. Are you setting any of the Boken environment variables that override the automatic BokehJS version selection? Are you loading BokehJS manually in raw HTML cells?