What causes UserErrorJniException?

The _JAVA_OPTIONS system environment variable on the SHIR host contains invalid or conflicting arguments. JVM memory settings (Xms/Xmx) set below the required threshold (minimum 8 GB for Parquet operations with Fabric Data Factory). A previous installation left conflicting JVM configuration in system environment variables. Multiple Java installations on the SHIR host with conflicting PATH entries

How do I fix UserErrorJniException?

Sign in to the machine hosting each SHIR node and check the _JAVA_OPTIONS system environment variable.. Set _JAVA_OPTIONS to '-Xms256m -Xmx16g' (ensure Xmx is at least 8 GB).. After updating the environment variable, restart all SHIR nodes.. Rerun the pipeline after restarting the integration runtime.

Medium severityfabricMicrosoft Fabric →

Microsoft Fabric Error:
UserErrorJniException

What does this error mean?

A Fabric Data Factory copy activity writing Parquet files failed because the Java Virtual Machine (JVM) could not start on the self-hosted integration runtime. This is caused by invalid global JVM arguments (an incorrect _JAVA_OPTIONS system variable) on the SHIR host machine.

Common causes

1The _JAVA_OPTIONS system environment variable on the SHIR host contains invalid or conflicting arguments
2JVM memory settings (Xms/Xmx) set below the required threshold (minimum 8 GB for Parquet operations with Fabric Data Factory)
3A previous installation left conflicting JVM configuration in system environment variables
4Multiple Java installations on the SHIR host with conflicting PATH entries

How to fix it

1Sign in to the machine hosting each SHIR node and check the _JAVA_OPTIONS system environment variable.
2Set _JAVA_OPTIONS to '-Xms256m -Xmx16g' (ensure Xmx is at least 8 GB).
3After updating the environment variable, restart all SHIR nodes.
4Rerun the pipeline after restarting the integration runtime.

Beyond the docs

Common practitioner solutions not covered in the official documentation.

1If multiple Java versions are installed, ensure the SHIR is using the correct JRE (check JAVA_HOME environment variable)

Frequently asked questions

Does this error affect Power BI reports in the same workspace?

Depends on the error type. Semantic model failures affect report freshness directly. Dataflow or pipeline failures may cascade into downstream semantic model failures.

How is debugging Fabric errors different from classic Power BI errors?

Fabric errors often require checking capacity utilization alongside the item-level error. The Fabric admin portal shows capacity pressure that Power BI Service doesn't expose.

Can Fabric errors be caused by capacity limits?

Yes — Fabric capacities have concurrent operation limits. An undersized capacity causes failures during peak usage.

Does this error appear in Power BI Desktop?

No — Fabric items are cloud-native. Desktop can connect to Fabric semantic models but cannot trigger or observe Fabric-specific errors.

Source · learn.microsoft.com/en-us/fabric/data-factory/connector-troubleshoot-parquet-format