Get certified for free when you join Fabric Data Days 2026 and dive into Fabric, Power BI, SQL, AI, and other essential data skills.
Join nowJuly 7 - July 17 | Round 2 of the Power BI Dataviz World Championships. Don't miss your chance! Learn more
when i try to refresh data or create a new dashboard
Expression.Error: Valur "Preferred" is not on of the correct type.
i did a test with a mysql database with only one simple table and I saw the same message error
Solved! Go to Solution.
Dear Ross73312, thanks a lot.
After playing and reviewing everything, I uninstalled the odbc connector from mysql and also uninstalled the powerbi desktop. Install everything from scratch on my laptop and it was fixed.
If i had to guess, i'm expecting your Preferred column is either of type Date or Number. You might have a step that is trying to set this column as a type such as that. In your new data, some value is appearing that is not of that type. For example if you was numbers, you might have a value that contains a dash, or a blank.
Dear Ross73312, thanks a lot.
After playing and reviewing everything, I uninstalled the odbc connector from mysql and also uninstalled the powerbi desktop. Install everything from scratch on my laptop and it was fixed.
Hello! I have also the same problem! Did you change anything in your database? You had errors in data types? I am still trying to figure out what's going on. I uninstalled and installed Power BI and ODBC Connector but nothing has changed!
Join us in Barcelona for FabCon and SQLCon, the Fabric, Power BI, SQL, and AI community event. Save €200 with code FABCMTY200.
Join Data Days 2026: 60 days of free live/on-demand sessions, challenges, study groups, and certification opportunities.
| User | Count |
|---|---|
| 28 | |
| 23 | |
| 18 | |
| 18 | |
| 15 |
| User | Count |
|---|---|
| 47 | |
| 44 | |
| 43 | |
| 35 | |
| 30 |