Wrong data refreshing

[Anonymous]

I upgraded my windows 7 to 10. Since the upgrade, everytime I refresh my report, I get different results in my desktop report as you can see. If I refresh multiple times with on-premises data gateway I always get correct results online. 

I tried to upgrade the .Net Framework and the result is the same. It occurs in all Win 10 pro that I had. The same report in Win 7 refresh correctly.

I think it only happens in reports with appended queries

I'm using Win 10 pt-PT PRO

Power BI pt-PT

I've noticed with other users that the issue occurs since last year with all power bi versions.

If I refresh 10 times, I will get 10 differents results (only with the Win 10). 

[v-haibl-msft]

@Anonymous

I cannot repro the same issue on my side. I suggest you to create a support ticket at http://support.powerbi.com (see bottom of page).

Best Regards,
Herbert

[InaNortje]

Hi @Anonymous

I had something very similar that I managed to resolve - hopefully this may help you.  

The conditions under which it occurred in my case were:

 - High volume source data from SQL

 - Subsequent merge with Excel data

What went wrong:

With a merge in the process and a large source table, Power Query seems to issue the query twice, selecting x records in the first query, and then total-x records in the second query.  It assumes that the order is the same (which in my case it wasn't), and then you get some records duplicating while others are dropped.

Resolution: 

 - Added an explicit "order by" clause to my SQL query

Interestingly, the SQL query didn't return high volume data.  It's the source table size that mattered.  In my case, the issue started once the source table size is 36 million records - even though my query only returned 13 thousand records.

Below is a link describing the full details of the issue that I had, and how I finally resolved it. 

https://community.powerbi.com/t5/Issues/Power-Query-Merge-yields-inconsistent-results/idi-p/119485

[Anonymous]

Hi @InaNortje,

Thanks for sharing your issue with me. That's exactly what I'm facing too. I had a conferance call with microsoft support sharing my environment, and they can't get a solution. They asked me to share some sample and printscreens to escalate the issue.