Forum Discussion
Power BI error: file 'xldc.cpp', line 3938, function 'XLAggImpl_Set<1,1>::Accumulate'
HI StefanGr,
Thank you for the update, your latest test provides valuable insight. Since the error still appears after removing all visuals and report pages, it suggests the issue is not with visuals or measures, but rather with the data model processing, such as data loading, calculated columns, or transformations. This supports your idea that the fact table may be the root cause.
It would be helpful to focus on the fact table, particularly the calculated columns. Try creating a copy of the PBIX file, remove all calculated columns from the fact table, and refresh. If the error disappears, reintroduce the columns one at a time to identify which one causes the issue. This step-by-step method can help isolate the problem.
Also, check the data quality and data types in the fact table. Mixed data types, unexpected nulls, or incorrect type conversions can cause internal aggregation errors. Setting data types explicitly in Power Query may help prevent this.
You could also test the fact table separately by loading it into a new blank PBIX file. Start with a few columns and add more gradually to see if a specific column or transformation triggers the error. Reviewing and disabling recent or complex Power Query steps may also help pinpoint the issue.
Lastly, since older versions of the report are failing too, the problem might be related to a recent engine or version change. Testing in the latest or a previous stable version of Power BI Desktop could help determine if the environment is a factor.
Thank you.
Hello v-sgandrathi : Thanks for following up. I was busy with other tasks and not time to troubleshoot the report.
Today I tried the ultimate strip down. I removed all report pages execpt for one and I removed all visuals from that page so that just some text fields and graphical elements remain on the page. Means there is no more measure or fact table used by this report page.
However, uploading this report to my cloud space, and trying to update this, the error persists.
I assume that updating the report also works through all steps to create the data model (importing tables, creating calculated columns in the model etc.). I can now try to remove calculated columns one by one to see which one is causing an issue, as I can be sure it's not coming from any of the visuals.
Or are there any other ideas?
Thanks!
BR, Stefan
HI StefanGr,
Thank you for the update, your latest test provides valuable insight. Since the error still appears after removing all visuals and report pages, it suggests the issue is not with visuals or measures, but rather with the data model processing, such as data loading, calculated columns, or transformations. This supports your idea that the fact table may be the root cause.
It would be helpful to focus on the fact table, particularly the calculated columns. Try creating a copy of the PBIX file, remove all calculated columns from the fact table, and refresh. If the error disappears, reintroduce the columns one at a time to identify which one causes the issue. This step-by-step method can help isolate the problem.
Also, check the data quality and data types in the fact table. Mixed data types, unexpected nulls, or incorrect type conversions can cause internal aggregation errors. Setting data types explicitly in Power Query may help prevent this.
You could also test the fact table separately by loading it into a new blank PBIX file. Start with a few columns and add more gradually to see if a specific column or transformation triggers the error. Reviewing and disabling recent or complex Power Query steps may also help pinpoint the issue.
Lastly, since older versions of the report are failing too, the problem might be related to a recent engine or version change. Testing in the latest or a previous stable version of Power BI Desktop could help determine if the environment is a factor.
Thank you.
Hello v-sgandrathi :
I finally found the rootcause, after step-by-step removal of groups of calculated columns from my fact sheet to identify which group the error comes from. Then finally removing column by column.That led to one column that is doing some text operations and clean-up, but did that in a not very robust way. Analyzing this DAX fomula with GenAI it turns out that it might crash the engine if the source column does not only have text values but also numberic values mixed in.
That makes sense, as by the time when the error in my report started, I changed the data that is loaded in my report and apparently in that new data there was a numeric value in that questionable source column. That led to the engine crash from that day on.
After improving the DAX formula for this column, the report updates normal now.Thanks for your support!
Hi StefanGr,
Thank you for sharing the update, it’s very helpful.
The issue makes sense since having both text and numbers in a column can cause engine errors if DAX expects only text. Nice work pinpointing the column and correcting the formula.
For future reference, it’s best to:
Check data types in Power Query
Use checks like ISNUMBER or ISTEXT in DAX to handle mixed values
Glad everything is working now.
Best regards,
Sahasra.