Data refresh error

Hello SaKhan 

The error message you’re encountering in Power BI indicates that the column `<oii>ScheduledEffort</oii>` in the table `<oii>Plan_Enhancement</oii>` contains duplicate values, which is not allowed for columns used as the primary key or on the “one” side of a many-to-one relationship.

Please check your source data for duplicates

Use the “Remove Duplicates” option under the Home tab to identify duplicates.

If duplicates exist but are unintended:
• Use Remove Duplicates in Power Query for the `<oii>ScheduledEffort</oii>` column.

if this is helpful please accept this solution 

Hi SaKhan 

The schedule refresh error in your Power BI dashboard is due to a duplicate value in the column ‘ScheduledEffort’ within the table ‘Plan_Enhancement’. This column is likely being used as a primary key or as the "one" side of a many-to-one relationship, where unique values are required. Even though your dataset was working fine for over a month, data refresh issues can arise due to changes in the underlying source data, even if you haven’t modified the report. This could be caused by new data being added, external updates, or changes in the data ingestion process. To resolve this, first, check the ‘Plan_Enhancement’ table in Power Query Editor or your source system to identify duplicate values in the ‘ScheduledEffort’ column. If duplicates exist, you may need to remove them, transform the column to ensure uniqueness, or modify relationships in Power BI. Additionally, review the data source update process to prevent such issues in future refreshes. If needed, you can also remove or modify the existing relationship in the Model view to allow duplicates.