Problems with the Jupyter notebook environment ("Lab")

Error message "Error in Authenticator.pre_spawn_start: ... 401: Unauthorized"

When a new user accesses the Lab in a new collab for the first time, it is possible, that the JuypterLab is not starting and instead shows a "...401 Unauthorized" message.

To fix this error, please access the "Drive" link in the collab once (the "Drive" is also in the left hand navigation menu of the Collab). After the "Drive" has been accesses once the JupyterLab should start.

No example notebooks in the Jupyter notebook environment ("Lab")

When starting the Jupyter notebook environment for the first time it takes about a minute (without visible "in progress" indication) until the example files appear in the file-chooser. Until then the list is just empty. So the fix here is "have a minute patience"

Timeout when starting the Jupyter notebook environment ("Lab")

It is possible, that accessing the "Lab" link results in a "timeout" message. This can happen, when the lab environment is started for the first time on one of the virtual machines providing the service, as the very first start per machine takes quite some time (in the order of 2 minutes). Accessing the "Lab" link again after a few minutes usually works.

Lab error message "Cannot open - Could not find path..."

Sometimes the Lab can not open the path /shared/name-of-the-collab, even though in the drive the path is already accessible (see the two screenshots below from the Lab and the Drive).

In the "drive" the path is visible:

BrainScaleS specific tips

The BrainScaleS external user chat has service announcements (e.g. when a system is down due to maintenance) and is also a good place to ask general questions.