We received the same error when our CI/CD pipeline deployed files from the repository to the workspace. The issue was that the imported files were of type "notebook" and not type "file". When we deleted the notebooks from the workspace and re-imported them as files, we no longer received the error. Take a look at your CI/CD pipeline, our DevOps engineer said the file types were intentionally being stripped from the files prior to upload. We're investigating updating the pipeline to not do so.