Data Model Errors in Power BI

PowerBI DARTS

This article may be helpful for Power BI report authors when the data model has issues.

Detailed Information

Check these items when you have issues with a data model.

Applied Steps in Power Query Editor

The "Applied Steps" in Query Editor will help you find the solution for an error. Go to each step and look at the query. Delete the unnecessary step(s). You can rename each applied step for future reference.

Query Settings pane in Power Query Editor with properties and applied steps listed.

Queries in Power Query Editor

Duplicate the table where the error occurs and delete unnecessary columns to test the error. Dealing with a smaller dateset will help with solving errors.
Un-checking the box for "Enable load" helps to speed up the refresh time for the new data preview.

list of function in queries and "Enable load" is checked and outlined with a red box,

Table Relation

Rule of thumb: DO NOT use bidirectional relationships in the model.

The relationship between a fact table and a dimension table is usually many to one. The direction should be from the dimension to the fact.
Watch for null/blank values
Read Relationship troubleshooting guidance page from Microsoft
Read bidirectional relationships and ambiguity in DAX page on SQLBI blog
Watch Power BI Row-Level Security And Where To Filter video from Guys in a Cube (around after 4 minutes)

Slicer

When slicers don't interact with each other, there is a way to make it work.

Create a simple measure in the fact table, such as COUNTROWS(table). The example below return the number of rows in the fact table.
```
CountRows = countrows(fact)
```
Click the slicer and add the measure in the Filters pane. Set the condition as "is greater than or equal to 1." Click the small icon for "Lock" and "invisible", and then click "Apply filter". Do the same to each slicer on every page.
Here are additional resources about setting slicers.