Strange red frames in JLab

Hello! In a Jupyterhub that I have running, I am seeing the following strange red frames (possibly containing an error message, but that’s hard to see) both in the notebook tabs, as well as in the tabs on the left side (for different views of the left panel). Any ideas on how to debug/solve this? Thanks!

This is a version issue that cropped up after JupyterLab 1.1 was released. There are 2 ways you can fix this:

  • If you can, upgrade to Jupyterlab 1.1.0 or 1.1.1 (pip install --upgrade jupyterlab==1.1)
  • If you must stay on JupyterLab 1.0.x, upgrade to JupyterLab 1.0.10.

Either of those should fix the DOM errors you’re seeing.