Weird localization problem in DAX editor 16. September 2014 Nico Jacobs Business Intelligence, Excel, Power BI, SQL Server BI (72) One of my students (thanks, Stefan!) discovered during the PowerBI course a bizarre localization issue in the DAX editor of Excel and SQL Server Data Tools, which is easy to replicate: Install Office 2013 or SQL Server data tools on a machine with a locale which uses a comma as decimal separator (I’m from Belgium, a Belgian locale will do). Then create a Power Pivot model, add a table to it, and in the Table editor create a calculated column which uses at least one parameterized function. In this function provide as an argument the constant string “,”. For instance you could use as an expression =IF(1=1;”,”). As soon as I enter this in the editor, the editor replaces the constant string “,” with “;”, but still shows in the outcome the correct value “,”. Something similar happens when I type a dot as constant string. When this is what I type in Power Pivot: This is what I get when I press enter in the expression editor: Notice how the formula in the editor uses a comma instead of a dot, but the evaluated expression (CalculatedColumn1 in my case) uses the dot I originally typed: what I see is not what I get. And to make things worse: when I edit the formula (e.g. adding an else parameter), it really starts to use the comma I never typed, and replaces in the expression the comma with a semi-column I never typed nor see in the evaluated column: So, be careful when using constant strings “.” or “,” in DAX!