azuredatastudio: ModuleNotFoundError: No module named 'jupyter_server.contents' switching to Python kernel

Started seeing this after the installing the 6.5.5 version of the notebook package for the python kernel. Unclear exactly what’s causing it currently though.

While this issue was caused by switching to 6.5.5 (through the RC1 build) it also affects stable so seems to be something related to the packages themselves.

Failed to change kernel. Kernel SQL will be used. Error was: Notebook process exited prematurely with error code: 1. StdErr Output: Traceback (most recent call last):
  File "C:\Users\chgagnon\AppData\Roaming\Python\Python38\site-packages\notebook\traittypes.py", line 235, in _resolve_classes
    klass = self._resolve_string(klass)
  File "C:\Users\chgagnon\AppData\Roaming\Python\Python38\site-packages\traitlets\traitlets.py", line 2009, in _resolve_string
    return import_item(string)
  File "C:\Users\chgagnon\AppData\Roaming\Python\Python38\site-packages\traitlets\utils\importstring.py", line 30, in import_item
    module = __import__(package, fromlist=[obj])
ModuleNotFoundError: No module named 'jupyter_server.contents'

Additional info:

1. Here’s the PR that introduced the line that’s failing : https://github.com/jupyter/notebook/pull/5957
2. Changing line 1411 in $(Python)\Python38\site-packages\notebook\notebookapp.py from

'jupyter_server.contents.services.managers.ContentsManager'

to

'jupyter_server.services.contents.manager.ContentsManager'

seems to fix the issue.