DataFlow fails to save with Unknown Error

[jmg80525]

Trying to create a dataflow to a folder that contains CSV files.  All the applied steps work, but when I try to save the dataflow it goes through all of the validation steps successfully, spins,  and then throws Can't Save Dataflow > UnknownError.  I have a Premium Per User license and the workspace is premium capacity.  Any ideas how to debug?  Also, with a Premium Per User license can I submit a support ticket. It's not obvious how to do it.

[jmg80525]

I should have clarified that I am using the Folder connection utilizing a UNC path that contain CSV files of the same schema.  It will connect fine and work through all the typical applied steps to create a query that contains all the rows from the all the CSV files.  For development purposes I want to only have the last (by timestamp) CSV file in the folder.  I utilize Table.LastN(Source, 1) step after the source step and this works fine.  I then create a parameter (number) to contain the same value of 1 and then replace the number option with the parameter (Table.LastN(Source, pDaysToKeep).  This will work in the Query Editor and I can continue to commit applied steps. However, the presence of this step with the number of rows option refering to a parameter is what keeps the query from saving. 

[v-jingzhan-msft · Accepted solution]

Hi @jmg80525 

Thank you for this information. Did you try to load the parameter? Based on my test, if I try to load the parameter, I have the same "UnknownError" when saving the dataflow. However if I don't load the parameter, I can save the dataflow successfully. Just keep the "Enable load" option unchecked as default and try saving again. 

This is probably not an issue due to the following dataflow limitation from Dataflows considerations and limitations:  

In Power BI dataflows, you can use parameters but you can't edit them unless you edit the entire dataflow. In this regard, parameters in dataflows behave similar to declared constants.

Best Regards,
Jing
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[v-jingzhan-msft]

Hi @jmg80525 

I cannot reproduce this error at my side. Sometimes this would be a temporary issue. Do you still have this error now when saving a dataflow that is connected to a folder?

If you still have this error, can you save a dataflow that is connected to a local file? 

If you create a dataflow connecting to the same folder in a shared capacity, will this error occur?

Do you have some computed tables in the dataflow by referencing some tables? 

In addition, with a PPU license you can submit a support ticket. Please refer to How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

Best Regards,
Jing
If this post helps, please Accept it as Solution to help other members find it. Appreciate your Kudos!