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5 common Power BI issues & how to fix them

11th November 2024

Power BI is a highly valuable tool for data analysis. However, when issues like broken visuals and slow report loading arise, they can significantly disrupt productivity.

Unfortunately, these problems aren’t only frustrating, but can also lead to delayed business insights and decision-making.

We’ve created this guide to help you overcome the most common Power BI issues. We cover the top five problems organisations face when using Power BI, and how to resolve them.

 

1. Slow report loading times

Slow-loading Power BI reports are one of the most common and frustrating issues users encounter. When this problem occurs, it can delay decision-making and reduce productivity.

The most common causes are large datasets that strain system resources and complex visuals with numerous data points. Inefficient DAX calculations, particularly in calculated columns, are also often a culprit, especially in large Power BI projects.

How to fix it

You can take the following steps to resolve this issue:

  • Implement data aggregations: Minimise the volume of aggregate data loaded into Power BI by creating pre-aggregated tables at the data source. This also improves performance when opening large Power BI Desktop files.
  • Simplify visuals: Avoid using resource-intensive custom graphics and reduce the number of visuals on each page of your reports to keep Power BI projects responsive.
  • Optimise DAX calculations: Use efficient columnar operations instead of row-by-row evaluations. Leverage variables or calculation groups to streamline complex logic in calculated columns for faster report performance.

 

2. Broken visuals or missing data

It’s also fairly common for Microsoft Power BI visuals to display incomplete data or to fail to render. This can lead to the misinterpretation of data and inaccurate insights.

Typically, this is caused by unstable data sources or outdated custom visuals. If neither of these is the source of the issue, then it may be due to version conflicts between Power BI Desktop and Power BI Service.

How to fix it

Here are the ways you can resolve issues with broken visuals and missing data:

  • Build data source redundancy: Create caching mechanisms or backup data sources so that data is available when your primary sources are unstable.
  • Conduct regular visual audits: Audit custom visuals regularly to check they’re compatible with the latest Power BI updates. It’s a good idea to subscribe to notifications from visual developers so you can stay up to date with updates and potential issues.
  • Version control documentation: Keep a detailed log of approved visuals and their versions. You can catch potential conflicts early by testing updates in a staging environment before you deploy them to production.

 

3. Data refresh failures

Accurate data and up-to-date figures are essential for things like quarterly reviews and leadership meetings. Yet, Power BI often fails to refresh data which can compromise data quality and disrupt these important activities.

The most common causes of these failures are expired credentials, gateway misconfiguration, and network connectivity problems.

How to fix it

The best practical solutions for data refresh failures are:

  • Good credential management: Make sure your organisation has a system for regularly updating credentials, especially when user roles change.
  • Verifying gateway configuration: Check that the Power BI on-premises data gateway is set up properly and that its connections to data sources are stable.
  • Automating and segmenting refreshes: Set automated refreshes to occur during off-peak hours to reduce network strain. If you have large datasets, break the updates into smaller, more manageable increments. This will reduce the risk of timeouts.

 

4. Query errors

When problems occur during the loading or data transformation process, it can prevent the query from executing correctly. They can be caused by problems like data type mismatches, syntax mistakes in Power Query, and missing columns or tables.

How to fix it

Here are the most effective fixes for Power BI query errors:

  • Data type validation: Check that there’s consistency between source data types and query expectations. You can explicitly set correct data types by using the “Changed Type” step in Power Query.
  • Syntax reviews: Closely inspect Power Query transformations for incorrect references and typos. You should also review and debug complex queries with the “Advanced Editor”.
  • Source data verification: Conduct regular audits of your source data and check that all referenced columns and tables exist.

 

5. Memory allocation errors

If Power BI runs out of available memory, you’ll start experiencing memory allocation errors. This is usually because you’re using oversized datasets, inefficient data models, or memory-intensive DAX calculations.

How to fix it

You can fix memory allocation errors by:

  • Using data reduction techniques: When you import data, apply filters that exclude irrelevant data. If you’re importing large datasets exceeding memory limitations, use DirectQuery mode.
  • Optimising data models: Simplify relationships between tables and remove unnecessary calculations or columns. You can identify memory-hungry tables and measures by using the Vertipaq Analyzer.
  • Enhancing query efficiency: Reduce Power BI’s workload by using query folding to push computations back to the data source.

 

FAQs

How can I access Power BI support?

If you’re unable to resolve your Power BI issues and require support, you should visit the Microsoft Power BI support page.

Does Power BI Pro experience fewer issues than the free version?

Users of Power BI Pro report a similar number of issues as those using the free version. However, the Pro version has some advantages that can help to mitigate certain issues, such as:

  • Increased storage capacity
  • More frequent data refreshes
  • Access to more data sources

Why are my Power BI reports loading slowly?

Slow report loading is often caused by large data volume, complex visuals, or inefficient DAX calculations. Optimising semantic models, removing unnecessary columns, and using composite models can help improve performance.

How can I keep my Power BI Desktop files manageable?

Large files often result from high data volume or overly complex composite models. Regularly pruning unnecessary columns, optimising semantic models, and reviewing data source settings helps keep files smaller and easier to maintain.

How do I optimise my data models for better performance?

Optimising data models involves removing unnecessary columns, aggregating large data volume, and carefully designing relationships. Using composite models can allow for more efficient storage and query performance.

 

Final Thoughts

Power BI is a popular and powerful tool but fairly common problems like broken visuals, slow-loading reports, and data refresh failures can disrupt your organisation’s workflows. So, use the fixes in this guide to get the most out of Power BI and ensure smooth performance.

If you’re looking to fully optimise your Power BI usage, sign up for Zenzero’s Microsoft 365 support service.

We ensure Power BI is fully integrated with your existing systems and data sources, and we’re experts at resolving any issues. Contact us today for your free consultation.

 

Sources:

https://www.codecreatorsinc.com/common-power-bi-errors-and-how-to-fix-them/

https://multishoring.com/blog/7-most-common-power-bi-issues-and-how-to-deal-with-them/

https://learn.microsoft.com/en-us/power-bi/troubleshoot/

https://medium.com/@jens.wienkamp/5-common-power-bi-issues-to-be-aware-of-before-they-arise-17e44aa1aa9d

https://www.vuepilot.com/support/article/troubleshooting-microsoft-power-bi-issues/

https://www.powerbiops.com/blog/power-bi-problems/

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