Jupyter Hub shows "Error Starting Kernel - Unhandeled error" without showing further information

I am using jupyter hub with multiple users. I have created new environment few days ago. It seemed to work, I left it for few days, and today when I try to open notebook and set kernel I have pop-up error message:

"Error Starting Kernel - Unhandled error"

I know two things that maybe related to this error:

1. The new environment set few days ago
2. I am running out of memory

I have read this post and I have chcked the version I have of jupyter_client (7.1.0) and jupyter_core (4.9.1) which seems to be more updated than the ones in the answer post, so I beleive that this is not the issue.

I have also tried to remove that environment but got error in the end:

[Errno 28] No space left on device

I have also tried just to remove some files I have to have memory but the delet is failing.

I am not sure if the source of the error is the environment or the memory or both, but need some clue to solve it.
My end goal is to have my jupyter hub working again- being able to set kernel and removing files.

I have had a similar issue and found the error regarding the logs. In my case, the issue was that the environment was located in the /root/.conda/ directory, which resulted in a PermissionDeniedError. Here, moving the environment and installing the kernelspec as described in the docs was the solution. You can do so with conda create NAME -p /path/to/NAME where NAME is the desired name of the environment and /path/to/ should be a location accessible to all users.