Dataflow gen2 Mashup exception error while writing to Warehouse/Lakehouse

[funtomas]

Hello team,

I am getting data from multiple Excel Sheets in one Excel document from Exchange server. Dataflow failed while writing data to table in Warehouse or Lakehouse.
Similar dataflow works. Only difference between these dataflow is that second one is only from one sheet.

Name:
WriteToDatabaseTableFrom_TransformForOutputToDatabaseTableFrom_TasksOtherSheets

Error:

Mashup Exception Expression Error Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Expression.Error: The value is not updatable. Details: Reason = Expression.Error;Detail = #table({"Change number", "Work order", "Task ID", "Description", "Asset", "Customer", "Location", "Status", "Priority", "Creation Date", "Scheduled start", "Scheduled finish", "Target start", "Target finish", "Owner group", "Owner", "Site"}, {});Microsoft.Data.Mashup.Error.Context = User

[v-cboorla-msft]

Hi @funtomas 

Welcome to Microsoft Fabric Community and thanks for posting your question here.

As I understand that you are getting data from multiple Excel Sheets in one Excel document from Exchange server and the Dataflow throws an error "The value is not updatable" while writing data to table in Warehouse or Lakehouse.

Certainly! The error message "The value is not updatable" means that the dataflow is attempting to write data to a table that cannot be updated. This could be due to the table being read-only, or because the dataflow is trying to insert or update data that does not match the table's schema.

And you have mentioned that similar dataflow is working because it is only using data from one sheet. This suggests that there is a problem with the data on one of the other sheets.

For example, the other sheets may contain data that is invalid, or that does not match the schema of the destination table. You can troubleshoot the problem by running the dataflow only from the problematic sheet. This will help you to identify which sheet is causing the error.

And the other possibility for getting the error - The dataflow may not be able to insert or update data if the data already exists in the destination table. This is because the destination table may have a unique key constraint, which means that each row must have a unique value for a specific column. If the dataflow tries to insert a new row with the same key value as an existing row, the dataflow will fail.

For more details please refer Data Factory Dataflow Gen2 limitations.

I hope this information is helpful. Please do let us know if you have any questions.

[funtomas · Accepted solution]

hello @v-cboorla-msft ,
Thanks a lot for looking into this. This certainly helped me to know more about error messages. Much appreciated! I did not expect so easy understanding of my problem and smart explanation.
However what I did was that I cancelled relation of my dataflow to Warehouse. Deleted Warehouse. Created new lakehouse. Linked dataflow to new table in the lakehouse and it works perfectly.

Thank you again!

[v-cboorla-msft]

Hi @funtomas 

Glad that your query got resolved. 
Please continue using Fabric Community for any help regarding your queries.