High severitysql
Power BI Refresh Error:
DELTA_PROTOCOL_CHANGED
What does this error mean?
The Delta table's protocol version was upgraded (by a writer using a newer Delta version) to a version that the current reader or writer does not support. The operation is blocked until the client upgrades.
Common causes
- 1A newer Databricks runtime or Delta Spark version wrote to the table and upgraded the protocol to use reader/writer features not available in the current runtime
- 2Delta Lake features such as Deletion Vectors, Column Mapping, or Liquid Clustering were enabled, bumping the minimum reader/writer version
- 3Multiple clusters with different DBR versions are writing to the same table
- 4An external tool (e.g., Apache Spark OSS) attempted to read a table written by Databricks with proprietary protocol features
How to fix it
- 1Upgrade the Databricks Runtime version on the failing cluster to a version that supports the table's current protocol.
- 2Check the required protocol with: `DESCRIBE DETAIL <table>` — look at `minReaderVersion` and `minWriterVersion`.
- 3If downgrading the protocol is acceptable, use `ALTER TABLE <table> SET TBLPROPERTIES ('delta.minReaderVersion' = '1', 'delta.minWriterVersion' = '2')` — only works if no incompatible features are active.
- 4Avoid mixing clusters with very different DBR versions writing to the same table.
- 5For external readers (non-Databricks), use Delta Sharing or export to a format the reader supports.