Problem with DataFormat.Error: We couldn't convert to Number.

[Anonymous]

Hi! 

I'm connecting to a data source via Custom Connector. When I check the query in the Query editor, I see that some columns have the error "DataFormat.Error: We couldn't convert to Number.". I would usually format the error column as TEXT but in this case, after formatting the column as TEXT, the Errors remain in place.

Background information: 

In query settings the steps are 

1. Source

2. Navigation

(3. Changed Type). 

In the Source step, the data is in Table, which I click and open thus ending in step Navigation. After these steps, the table is opened and I can see the errors the first time. The error columns seem to be preset as decimal values. If I try to change the type of the column to Text, nothing happens and the errors remain.

How can I format the columns as text?

Thanks, the help is much appreciated.

[ImkeF]

Hi @Anonymous ,

not sure if I understood your description correctly. There is actually just one thing you can do here:

Delete the last step "Changed Types". If the error persists, it is caused by a transformation in the custom connector itself already. That means the the custom connector has to be adjusted.

[Anonymous · Accepted solution]

Hi @ImkeF , 

Sorry for the unclear description. However, you were still able to get to the point. It seems that Custom Connector formatting the data before uploading to the Power BI/Power Query Editor was the problem.

For future reference, I needed to download & install Visual Studio and install Power Query SDK extension to the Visual Studio. After that, I opened the Custom Connector .sln file in the Visual Studio and edited the code in a way that the data type was set to required columns as text instead of number. After that, from top ribbon click Build solution and you may find the updated .mez file in the Custom Connect files in "CustomConnector(name)/bin/debug. Finally, put this .mez file to the documents/Power BI Desktop/Custom Connector folder. 

The process was fairly easy, as long as you have access to the Custom Connector files!

Thank you,