Forum Discussion
Strange Error - After transforming data - Cannot find Column
Hi
Have a strange error happening that I can't understand.
I transform my data expanding a column 'divisionids'. I close and Apply.
I expand to New Rows.
The data is there.
I hit close and apply. And then as it refreshes. It cannot find the column it just expanded
Any idea what is happening?
hi HankScorpio2 ,
Hey, just checking, when you expand divisionIds in the Power Query editor and immediately hit Refresh Preview (before applying), does it still show the values without errors? Sometimes with custom connectors, the preview is cached, but the actual refresh call can return slightly different schema (e.g., column renamed, case change, or missing entirely in certain calls). If the backend doesn’t always return divisionIds, Power BI will drop that column on load and throw this error. You might need to add a step to handle missing columns (like Table.AddColumn with a default value) before expanding.
Regards,
Akhil.
7 Replies
Hi HankScorpio2
What is the data source, and have you tried refreshing it on the Power Query side before clicking close and apply button to check if it shows any errors?
Its a custom connector I wrote. I set up the transform yesterday in Powerbi and it was all working. I created some measures. I returned to it today and received this error. So I created a new blank report and connected to the data source again. It retrieves the data and shows that there are dividionids. Its just when it goes to refresh it can't find the column it just pulled.
does it show an error in the last step of the query?
starting to think this might be interent related. Even though I have high speed over 100mbps I also just tested and had 6% packet loss. Do these sort of errors usually relate to something like that?
hi HankScorpio2 ,
Hey, just checking, when you expand divisionIds in the Power Query editor and immediately hit Refresh Preview (before applying), does it still show the values without errors? Sometimes with custom connectors, the preview is cached, but the actual refresh call can return slightly different schema (e.g., column renamed, case change, or missing entirely in certain calls). If the backend doesn’t always return divisionIds, Power BI will drop that column on load and throw this error. You might need to add a step to handle missing columns (like Table.AddColumn with a default value) before expanding.
Regards,
Akhil.Thanks for the thoughtful response. I have tried so much to troubleshoot it. Ultimately I have rewritten the connector to return a table and have more error handling. This did solve it. It is somewhat of an anomaly as the connector and PowerBi had previosuly worked. Maybe its an error that saved me from publishing the report to the business and then having greater issues down the track.
