What causes UNRESOLVED_ROUTINE?

Calling a function that exists in another schema or catalog without fully qualifying its name. UDF registered in a different SparkSession or cluster that is no longer active. Typo in the function name. Unity Catalog function not yet created or created in a different schema than the current `USE SCHEMA`. Using a function from a library (e.g., `dbt_utils`) that is not installed as a Unity Catalog function

How do I fix UNRESOLVED_ROUTINE?

Verify the function name and spelling with `SHOW FUNCTIONS LIKE ' *'`. Fully qualify Unity Catalog functions: ` . . ()`. If the function is a UDF, ensure it is (re)registered in the current session or cluster init script. For third-party functions, check that the associated library or wheel is attached to the cluster or SQL warehouse. Use `DESCRIBE FUNCTION ` to confirm the function exists and is accessible

Medium severityquery

Power BI Refresh Error:
UNRESOLVED_ROUTINE

What does this error mean?

Spark SQL could not resolve a function name to any built-in function, registered UDF, or Unity Catalog function. The function is unknown in the current catalog and schema context.

Common causes

1Calling a function that exists in another schema or catalog without fully qualifying its name
2UDF registered in a different SparkSession or cluster that is no longer active
3Typo in the function name
4Unity Catalog function not yet created or created in a different schema than the current `USE SCHEMA`
5Using a function from a library (e.g., `dbt_utils`) that is not installed as a Unity Catalog function

How to fix it

1Verify the function name and spelling with `SHOW FUNCTIONS LIKE '<name>*'`
2Fully qualify Unity Catalog functions: `<catalog>.<schema>.<function>()`
3If the function is a UDF, ensure it is (re)registered in the current session or cluster init script
4For third-party functions, check that the associated library or wheel is attached to the cluster or SQL warehouse
5Use `DESCRIBE FUNCTION <name>` to confirm the function exists and is accessible

Frequently asked questions

How are Unity Catalog functions different from session UDFs?

Unity Catalog functions are persisted, versioned, and governed — they survive cluster restarts and are accessible across workspaces. Session UDFs are ephemeral and must be re-registered each session.