This is a model that has been running for some time and nothing was changed of recent, so as much as what you said makes sense, it was not the issue.

I finally resolved the matter by changing the version of the cluster. I realized that the latest cluster is using the latest version of python which was just released 2 days to the error above. By changing the cluster version to 9.1 LTS, the error message no longer came up. Weird one, I know right.