Uncaught exection GET /api/kernel error message in notebook

Does someone here have experience on troubleshooting kernel errors?

When creating a new notebook we get an Uncaught exection GET /api/kernel error message.

Does this error involve conflicts in packages ?

jupyter --version

jupyter core     : 4.6.1
jupyter-notebook : 6.0.2
qtconsole        : 4.6.0
ipython          : 7.10.1
ipykernel        : 5.1.3
jupyter client   : 5.3.4
jupyter lab      : 1.2.3
nbconvert        : 5.6.1
ipywidgets       : 7.5.1
nbformat         : 4.4.0
traitlets        : 4.3.3

pip list:

alabaster (0.7.12)
anchor-exp (0.0.0.6)
appdirs (1.4.4)
argh (0.26.2)
asn1crypto (1.2.0)
astroid (2.3.3)
astropy (3.2.3)
atomicwrites (1.3.0)
attrs (19.3.0)
autopep8 (1.4.4)
Babel (2.7.0)
backcall (0.1.0)
backports.functools-lru-cache (1.6.1)
backports.os (0.1.1)
backports.shutil-get-terminal-size (1.0.0)
backports.tempfile (1.0)
backports.weakref (1.0.post1)
beautifulsoup4 (4.8.1)
biopandas (0.2.4)
bitarray (1.1.0)
bkcharts (0.2)
black (19.10b0)
bleach (3.1.0)
blis (0.4.1)
bokeh (1.4.0)
boto (2.49.0)
boto3 (1.10.36)
botocore (1.13.36)
Bottleneck (1.3.1)
CacheControl (0.12.6)
cachy (0.3.0)
catalogue (0.0.8)
cchardet (2.1.5)
certifi (2019.11.28)
cffi (1.13.2)
chardet (3.0.4)
cleo (0.7.6)
Click (7.0)
click-default-group (1.2.2)
clikit (0.4.3)
cloudpickle (1.2.2)
clyent (1.2.1)
colorama (0.4.1)
contextlib2 (0.6.0.post1)
cryptography (2.8)
cycler (0.10.0)
cymem (2.0.3)
Cython (0.29.14)
cytoolz (0.10.1)
dash (1.7.0)
dash-core-components (1.6.0)
dash-html-components (1.0.2)
dash-renderer (1.2.2)
dash-table (4.5.1)
dask (2.9.0)
datapackage (1.10.0)
decorator (4.4.1)
defusedxml (0.6.0)
diff-match-patch (20181111)
distributed (2.9.0)
docutils (0.15.2)
entrypoints (0.3)
et-xmlfile (1.0.1)
fastcache (1.1.0)
filelock (3.0.12)
flake8 (3.7.9)
Flask (1.1.1)
Flask-Compress (1.4.0)
fsspec (0.6.0)
future (0.18.2)
gevent (1.4.0)
glob2 (0.7)
gmpy2 (2.0.8)
gnureadline (8.0.0)
goodtables (2.4.1)
greenlet (0.4.15)
h5py (2.9.0)
HeapDict (1.0.1)
helpdev (0.7.1)
html5lib (1.0.1)
idna (2.8)
ijson (2.5.1)
imageio (2.6.1)
imagesize (1.1.0)
imbalanced-learn (0.6.1)
importlib-metadata (1.2.0)
intervaltree (3.0.2)
ipykernel (5.1.3)
ipython (7.10.1)
ipython-autotime (0.1)
ipython-genutils (0.2.0)
ipywidgets (7.5.1)
isodate (0.6.0)
isort (4.3.21)
itsdangerous (1.1.0)
jdcal (1.4.1)
jedi (0.14.1)
jeepney (0.4.1)
Jinja2 (2.10.3)
jmespath (0.9.4)
joblib (0.14.0)
json5 (0.8.5)
jsonlines (1.2.0)
jsonpointer (2.0)
jsonschema (3.2.0)
jupyter (1.0.0)
jupyter-client (5.3.4)
jupyter-console (6.0.0)
jupyter-contrib-core (0.3.3)
jupyter-contrib-nbextensions (0.5.1)
jupyter-core (4.6.1)
jupyter-highlight-selected-word (0.2.0)
jupyter-latex-envs (1.4.6)
jupyter-nbextensions-configurator (0.4.1)
jupyterlab (1.2.3)
jupyterlab-server (1.0.6)
keyring (19.2.0)
kiwisolver (1.1.0)
lazy-object-proxy (1.4.3)
libarchive-c (2.8)
lime (0.1.1.36)
linear-tsv (1.1.0)
llvmlite (0.31.0)
locket (0.2.0)
lockfile (0.12.2)
lxml (4.4.2)
MarkupSafe (1.1.1)
matplotlib (3.1.1)
matplotlib-venn (0.11.5)
mccabe (0.6.1)
mistune (0.8.4)
mock (3.0.5)
more-itertools (7.2.0)
mpmath (1.1.0)
msgpack (0.6.1)
multipledispatch (0.6.0)
murmurhash (1.0.2)
nbconvert (5.6.1)
nbformat (4.4.0)
networkx (2.4)
nltk (3.4.5)
nose (1.3.7)
notebook (6.0.2)
numba (0.46.0)
numexpr (2.7.0)
numpy (1.17.4)
numpydoc (0.9.1)
olefile (0.46)
openpyxl (3.0.2)
packaging (19.2)
pandas (0.25.3)
pandocfilters (1.4.2)
parso (0.5.1)
partd (1.1.0)
pastel (0.2.1)
path.py (12.0.2)
pathlib2 (2.3.5)
pathspec (0.8.0)
pathtools (0.1.2)
patsy (0.5.1)
pep8 (1.7.1)
pexpect (4.7.0)
pickleshare (0.7.5)
Pillow (6.2.1)
pip (9.0.1)
pkginfo (1.5.0.1)
plac (1.1.3)
plotly (4.4.1)
pluggy (0.13.1)
ply (3.11)
poetry (1.0.5)
poetry-core (1.0.0a1)
preshed (3.0.2)
prometheus-client (0.7.1)
prompt-toolkit (2.0.9)
psutil (5.6.7)
psycopg2 (2.8.4)
ptyprocess (0.6.0)
py (1.8.0)
pycodestyle (2.5.0)
pycosat (0.6.3)
pycparser (2.19)
pycrypto (2.6.1)
pydocstyle (4.0.1)
pydqc (0.1.0)
pyflakes (2.1.1)
Pygments (2.5.2)
pylev (1.3.0)
pylint (2.4.4)
Pympler (0.7)
pyodbc (4.0.27)
pyOpenSSL (19.1.0)
pyparsing (2.4.5)
pyrsistent (0.15.6)
PySocks (1.7.1)
pytest (5.3.1)
pytest-arraydiff (0.3)
pytest-astropy (0.6.0)
pytest-astropy-header (0.1.1)
pytest-doctestplus (0.5.0)
pytest-openfiles (0.4.0)
pytest-remotedata (0.3.2)
python-dateutil (2.8.1)
python-jsonrpc-server (0.3.2)
python-language-server (0.31.2)
pytz (2019.3)
PyWavelets (1.1.1)
pyxdg (0.26)
PyYAML (5.3.1)
pyzmq (18.1.0)
q (2.6)
QDarkStyle (2.7)
QtAwesome (0.6.0)
qtconsole (4.6.0)
QtPy (1.9.0)
readline (6.2.4.1)
regex (2020.10.28)
requests (2.22.0)
requests-toolbelt (0.8.0)
retrying (1.3.3)
rfc3986 (1.3.2)
rope (0.14.0)
Rtree (0.8.3)
s3transfer (0.2.1)
scikit-image (0.15.0)
scikit-learn (0.21.3)
scipy (1.3.2)
seaborn (0.9.0)
SecretStorage (3.1.1)
Send2Trash (1.5.0)
shellingham (1.3.2)
simpleeval (0.9.10)
simplegeneric (0.8.1)
singledispatch (3.4.0.3)
six (1.13.0)
snowballstemmer (2.0.0)
sortedcollections (1.1.2)
sortedcontainers (2.1.0)
soupsieve (1.9.5)
spacy (2.2.3)
Sphinx (2.2.2)
sphinxcontrib-applehelp (1.0.1)
sphinxcontrib-devhelp (1.0.1)
sphinxcontrib-htmlhelp (1.0.2)
sphinxcontrib-jsmath (1.0.1)
sphinxcontrib-qthelp (1.0.2)
sphinxcontrib-serializinghtml (1.1.3)
sphinxcontrib-websupport (1.1.2)
SQLAlchemy (1.3.11)
srsly (0.2.0)
statistics (1.0.3.5)
statsmodels (0.10.1)
sympy (1.4)
tables (3.6.1)
tableschema (1.12.0)
tabulator (1.31.0)
tblib (1.5.0)
terminado (0.8.3)
testpath (0.4.4)
thinc (7.3.1)
toml (0.10.2)
tomlkit (0.5.11)
toolz (0.10.0)
tornado (6.0.3)
tqdm (4.40.0)
traitlets (4.3.3)
typed-ast (1.4.1)
ujson (1.35)
unicodecsv (0.14.1)
urllib3 (1.25.7)
wasabi (0.4.2)
watchdog (0.9.0)
wcwidth (0.1.7)
webencodings (0.5.1)
Werkzeug (0.16.0)
widgetsnbextension (3.5.1)
wrapt (1.11.2)
wurlitzer (2.0.0)
xlrd (1.2.0)
XlsxWriter (1.2.6)
xlwt (1.3.0)
yapf (0.28.0)
zict (1.0.0)
zipp (0.6.0)

Nothing about those versions should lead to that 500. I just recreated your environment and everything works fine. Can you restart your notebook server using the --debug flag and share your output here?

> jupyter notebook --debug
1 Like

We solved this problem by using another browser (from Midori to Firefox).

Debugging did not result in usable info.
After troubleshooting a working image and a failing image, we found out that the new webkit-package crashed the API-calls to the kernel.