Hi, I'm Tom Blessing. I'm an expert at helping small to mid-sized companies adopt Power BI. I'm also a recovering investment banker, with deep experience applying technology to otherwise manual data problems. I have dual degrees in Finance and Technology Management from Indiana University.

Resources to help build your fundamentals: Learning Power BI? Data fundamentals are critical for this process to be easier. I've assembled a few DataCamp courses to help. I earn a small commission if you click and purchase.

Introduction to Power BI course: Master Power BI basics and learn to build impactful reports.

Exploratory Data Analysis in Power BI course: Learn about Power BI's Exploratory Data Analysis (EDA) and enhance your reports.

Introduction to SQL course: Learn how to create and query relational databases using SQL in just two hours.

Introduction to DAX course: Learn the fundamentals of Data Analysis Expressions (DAX) such as calculated columns, tables, and measures.

Database Design course: Learn to design databases in SQL to process, store, and organize data in a more efficient way.

One of Power BI's key features is data refresh, which ensures that your reports and dashboards always display up-to-date information.

However, there may be instances when your Power BI dataset doesn't refresh as expected, leading to outdated data.

In this blog post, we'll explore some common reasons why Power BI may not be refreshing and how to troubleshoot these issues effectively.

1. Data Source Connection Issues:

   • Connection Settings: The first step in data refresh is establishing a connection to your data source. Ensure that your data source's connection settings are correctly configured in Power BI. Check credentials, server addresses, and authentication methods. 

   • Firewalls and Security: Firewalls or security settings on your data source may block the connection. Collaborate with your IT department to ensure that Power BI has the necessary permissions to access the data source.

2. Scheduled Refresh Configuration:

   • Scheduled Refresh: Power BI allows you to set up scheduled refreshes for your datasets. Make sure you have scheduled refresh enabled and configured correctly for your dataset. Keep in mind that the frequency of refreshes may depend on your Power BI subscription. 

   • Data Source Dependencies: If your dataset relies on data from multiple sources, ensure that the refresh settings for each source are synchronized. A failure in one source's refresh can affect the entire dataset.

3. Data Transformation Errors:

   • Power Query Errors: If you're using Power Query for data transformations, check your query logic for errors. Incorrect transformations can cause refresh failures. Review the Query Editor and test your transformations step by step. 

   • Custom Functions: If you've incorporated custom functions in your queries, ensure they are functioning correctly and that any external dependencies are accessible during the refresh.

4. Data Source Changes:

   • Schema Changes: If the schema of your data source changes, such as column names or data types, your Power BI dataset may fail to refresh. Update your Power Query transformations to accommodate these changes.

   • Data Availability: Ensure that the data source is available during the scheduled refresh times. If the source is undergoing maintenance or downtime, it may cause refresh failures.

5. Resource Limitations:

   • Dataset Size: Large datasets can strain system resources and lead to refresh failures. Consider optimizing your data model by removing unnecessary columns or aggregating data where possible.

   • Power BI Service Limitations: Be aware of the limitations imposed by your Power BI service plan. Different plans have varying capabilities and refresh frequency options.

6. Data Load Failures:

   • Data Load Errors: Review the "Data" Pane to identify specific errors during the refresh process. A little red triangle will appear next to any fields that failed to load.

   • Data Connection Timeout: Slow or unreliable network connections can lead to data load failures. Ensure a stable network connection during refresh.

7. Scheduled Refresh Times:

   • Scheduled Time Conflicts: Make sure that your dataset's refresh schedule does not conflict with other maintenance or backup activities on your data source.

8. Power BI Service Issues:

   • Service Outages: Sometimes, the Microsoft or the Power BI service itself may experience downtime or performance issues, which can impact dataset refreshes. Check the Service Status page for updates on any service-related problems. 

Conclusion

Data refresh is a critical aspect of maintaining the accuracy and relevance of your Power BI reports and dashboards. When Power BI is not refreshing as expected, it's essential to systematically troubleshoot and identify the underlying issues. By following the steps outlined in this blog post, you can diagnose and resolve refresh problems.