Spyder 4.0 spyder-notebook not working

[Marcin Hołdyński]

Hello,

Great work with Spyder IDE. After upgrading to Spyder 4.0 spyder notebook is not visible. It's still in the installed package list but there is not any tab in main window or in View>Panes.

Info:

Operating System: Ubuntu 19.04
                 Kernel: Linux 5.0.0-37-generic
        Architecture: x86-64

Dependencies:

cloudpickle >=0.5.0          :  1.2.2 (OK)
pygments >=2.0               :  2.5.2 (OK)
qtconsole >=4.6.0            :  4.6.0 (OK)
nbconvert >=4.0              :  5.6.1 (OK)
sphinx >=0.6.6               :  2.2.2 (OK)
pylint >=0.25                :  2.4.4 (OK)
psutil >=0.3                 :  5.6.7 (OK)
qtawesome >=0.5.7            :  0.6.0 (OK)
qtpy >=1.5.0                 :  1.9.0 (OK)
pickleshare >=0.4            :  0.7.5 (OK)
zmq >=17                     :  18.1.0 (OK)
chardet >=2.0.0              :  3.0.4 (OK)
numpydoc >=0.6.0             :  0.9.1 (OK)
spyder_kernels >=1.8.1;<2.0.0:  1.8.1 (OK)
qdarkstyle >=2.7             :  2.7 (OK)
atomicwrites >=1.2.0         :  1.3.0 (OK)
diff_match_patch >=20181111  :  20181111 (OK)
intervaltree                 :  None (OK)
watchdog                     :  None (OK)
keyring                      :  None (OK)
pexpect >=4.4.0              :  4.7.0 (OK)
pympler                      :  None (OK)
sympy >=0.7.3                :  1.4 (OK)
cython >=0.21                :  0.29.14 (OK)
IPython >=4.0                :  7.10.1 (OK)
matplotlib >=2.0.0           :  3.1.1 (OK)
pandas >=0.13.1              :  0.25.3 (OK)
numpy >=1.7                  :  1.17.4 (OK)
scipy >=0.17.0               :  1.3.1 (OK)
pyls >=0.31.2;<0.32.0        :  0.31.2 (OK)
xdg >=0.26                   :  0.26 (OK)
rtree >=0.8.3                :  0.8.3 (OK)

Thanks in advance for the support.

Marcin