The only thing I can think of is that it may still be storing the id of cluster “AAA” from before your year off, and it keeps associating it because of the cluster name. In other words, you could have:

• Cluster AAA (old) - ID: XXXXXX - Runtime version 15.2

• Cluster AAA (new) - ID: BBBBB - Runtime version 16.4

Your notebook may still have the old ID XXXXX saved, but since it matches the name AAA, it triggers that error. The other option would be to do a reattach with Serverless and try again, or restart the cluster that is currently conflicting.

Also, restarting the notebook session.

Let us know!