Hi @Johan Rex​ We checked with databricks connect team, this issue can happen when the library is too large to upload,

Databricks recommends that you use dbx by Databricks Labs for local development instead of Databricks Connect. Databricks plans no new feature development for Databricks Connect at this time. Also, be aware of the limitations of Databricks Connect.

https://docs.databricks.com/dev-tools/databricks-connect.html

https://docs.databricks.com/dev-tools/dbx.html