Hi @dperkins 

The error is likely due to a mismatch between your delta-spark library and the Databricks Runtime. The runtime uses Spark 3.5.2 and Scala 2.13 (with Delta Lake 3.3.1), so ensure your JAR is built with these versions.
It’s best to remove the Delta dependency from your JAR (or mark it as provided) and avoid shading Delta classes to prevent conflicts.