What causes Query timeout expired?

The source table grew significantly larger and the query no longer completes within the timeout. Missing or stale database indexes causing a full table scan on large tables. A blocking query on the source database holding locks and preventing the Power BI query from completing. The dataset query is not incremental and re-reads the entire history on every refresh. Premium capacity or gateway resource contention slowing down query execution

How do I fix Query timeout expired?

Run the refresh query directly on the database (SSMS, psql, etc.) with query timing to see how long it actually takes.. Check for missing indexes on the columns used in WHERE, JOIN, and ORDER BY clauses.. Implement incremental refresh in Power BI Desktop to only query new or modified rows.. Query aggregate tables or materialized views on the source instead of raw fact tables.. If using DirectQuery, consider switching to Import mode with scheduled refresh for large datasets.. For Premium, check capacity utilization — a saturated capacity slows all queries running on it.

High severityquery

Power BI Refresh Error:
Query timeout expired

What does this error mean?

The data source query ran longer than the allowed timeout period and was cancelled. Power BI enforces query timeouts to prevent a single dataset from consuming resources indefinitely.

Common causes

1The source table grew significantly larger and the query no longer completes within the timeout
2Missing or stale database indexes causing a full table scan on large tables
3A blocking query on the source database holding locks and preventing the Power BI query from completing
4The dataset query is not incremental and re-reads the entire history on every refresh
5Premium capacity or gateway resource contention slowing down query execution

How to fix it

1Run the refresh query directly on the database (SSMS, psql, etc.) with query timing to see how long it actually takes.
2Check for missing indexes on the columns used in WHERE, JOIN, and ORDER BY clauses.
3Implement incremental refresh in Power BI Desktop to only query new or modified rows.
4Query aggregate tables or materialized views on the source instead of raw fact tables.
5If using DirectQuery, consider switching to Import mode with scheduled refresh for large datasets.
6For Premium, check capacity utilization — a saturated capacity slows all queries running on it.

Frequently asked questions

Does this error only affect the dataset or also the report?

The error occurs during the refresh — if the refresh fails, the report shows the last successfully loaded data, not an error. Users won't see a broken report, but the data will be stale.

How do I find which Power Query step is causing the error?

Open Power BI Desktop and attempt a refresh. Power Query highlights the failing step in the Query Editor. The error message typically includes the table name and step name.

Can query errors be caused by data changes in the source?

Yes — if the source returns a data type the query doesn't expect (e.g., a null value in a previously non-nullable column), the query evaluation fails.

Does this error affect all tables in the dataset?

Usually only the table whose query evaluation failed. Other queries in the dataset may succeed unless they depend on the failed query's output.

Source · learn.microsoft.com/en-us/power-bi/enterprise/service-premium-large-models