Applies to Product - Power Apps
What’s happening?
Customers are encountering the error message "Evaluation was cancelled" while attempting to migrate items from a SharePoint list, which contains a large number of records organized in a folder structure, to Dataverse using dataflow.
Reason:
The error is primarily caused by the limitations of the Power Query Online (PQO) editor, which has a ten-minute evaluation timeout. Additionally, SharePoint throttles requests when excessive calls are made, leading to delays and timeouts during data retrieval. The complexity and size of the data being processed can also contribute to this.
Resolution:
- Reduce Data Size: It is recommended to split the data into smaller batches. For instance, try fetching 250 records at a time instead of larger batches to avoid hitting the ten-minute evaluation timeout.
- Optimize Queries: Use the query editor to refine all steps before adding filters. Ensure that unnecessary columns are removed and record columns are expanded before applying any filters.
- Schedule Dataflow Refresh: Identify low-traffic times for the SharePoint service and schedule the dataflow refresh during those periods to minimize throttling issues.
- Use Alternative Methods: If the migration is a one-time task, consider exporting the entire SharePoint list to an Excel file and then uploading it back to SharePoint. Use the Excel connector in Dataflow to retrieve the data, as it uses fewer requests and is less likely to encounter throttling errors.
- Monitor Query Performance: Click on each step in the "Applied steps" section of the query editor to monitor how long each step takes to evaluate. This can help identify which specific step is causing delays or failures.