DataflowGen2 in Fabric refresh issue

[Shiva123]

Hi All , 

I am facing issue in Date table. I created Date table in DataflowGen2 with some logics and I want to give its destination to Fabric WH.

I also have other tables which have source and destination as WH but Date table is getting error that is refresh status is showing error. 

Errors are 

There was a problem refreshing the dataflow: 'Something went wrong, please try again later. If the error persists, please contact support.'. Error code: ActionUserFailure. (Request ID: fbc00919-af99-441b-b2fc-e9d8511aa9b2).

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Date_WriteToDataDestination: There was a problem refreshing the dataflow: 'Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Expression.Error: We can't update the table. The type of column 'Date' doesn't match the type of the column in the table. Details: Reason = Expression.Error;ErrorCode = 10557;Microsoft.Data.Mashup.Error.Context = User'. Error code: Mashup Exception Expression Error. (Request ID: fbc00919-af99-441b-b2fc-e9d8511aa9b2).

How to resolve it ?

[v-priyankata]

Hi @Shiva123 

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[Shiva123 · Accepted solution]

Thanks all who gave responses .
I got solution for this . 
Steps I followed 
1.First I changed data type in Dataflow from Date to DateTime 
2.I also changed structure of table in Warehouse . initially it was Date , I changed to DateTime(6)

Then published dataflow gen 2 . error gone and data stored from Dataflow to WH 

Thanks and regards 
Shiva.

[Shiva123]

Thanks @anilelmastasi 

Intitially only I observed it . In dataflow gen2 Date format is "MM-DD-YYYY" , In WH format is "YYYY-MM-DD".
1.if I consider this is route cause how come it refreshed yesterday ? 

2. I also try to change the date fomrat in Dataflow gen 2 seems not having option where can i find it (Need transormation in existing column only) ? 

[anilelmastasi]

You are welcome @Shiva123 ,

1.Even if the date format appears as MM-DD-YYYY in Dataflow Gen2 and YYYY-MM-DD in WH, what truly matters is the underlying data type, not the visual format.

It might have worked yesterday because:

The data values didn't trigger any parsing issues (e.g., 04-28-2025 could be read)

But now:

New data values might have ambiguous dates (e.g., 13-04-2025, which is invalid in MM-DD-YYYY), leading to failure.

2. Dataflow Gen2 does not let you directly change "format" like MM-DD-YYYY vs YYYY-MM-DD — that’s only how it’s shown.

What you must ensure is that the column is of proper date data type, not text.

If this solved your issue, please mark it as the accepted solution. ✅

[anilelmastasi]

Hello @Shiva123 ,

The error you're facing while refreshing your Date table from Dataflow Gen2 to Microsoft Fabric Warehouse is likely due to a data type mismatch between the column in your dataflow (source) and the corresponding column in the destination Fabric WH table.

Check the column type in Dataflow Gen2:

Open the Power Query editor for your dataflow.

Look at the data type of the 'Date' column.

Ensure it is explicitly set as date (not datetime or text).

Check the target table schema in Fabric WH:

Go to Fabric WH and inspect the schema of the destination table.

Make sure the 'Date' column is of the same type as in your dataflow (date if that’s what you defined).

Update column types to match:

If the Dataflow column is datetime but the WH expects date, apply a transformation in Power Query:

Table.TransformColumnTypes(#"Previous Step", {{"Date", type date}})

If this solved your issue, please mark it as the accepted solution. ✅