12.1.12 - 2026-11-05

Improvements

• Upload gets client-side file selection limits: MaxFileSize and AllowedExtensions reject files before they are uploaded and the new Rejected event reports each rejected file with a UploadRejectionReason of FileTooLarge or ExtensionNotAllowed (#2802). AllowedExtensions entries without a leading dot such as "pdf" are accepted and normalized to ".pdf" instead of throwing from OnParametersSet, which on Blazor Server terminated the circuit, and the limits are no longer re-sent to the browser right after the handler is created. Thanks to @Radium001!

Fixes

• DataGrid positions frozen columns by their measured widths instead of a 200px stand-in for columns without a Width. With several frozen columns of which only some had a width, the following frozen cells were pinned too far from the previous one, which left a blank strip between them and let them cover the first scrolling column. The offsets are now measured from the frozen header cells and follow container resizes, column resizes and columns being shown or hidden. Fixes #2804
• DatePicker dims the days of the adjacent months with a colour instead of a doubled opacity so they meet WCAG AA contrast. The rz-calendar-other-month class was applied to both the day cell and the span inside it and the opacity rule matched both, so those days rendered at 0.25 opacity. The new --rz-datepicker-calendar-other-month-color variable defaults to --rz-text-secondary-color and the hover, focused, today, range and selected states keep their colours. Fixes #2803
• Gantt timeline header cells match the row grid at every zoom level. The timeline table renders a colgroup with one col per column, so at the Year and Years zoom levels the month and quarter headers no longer drift from the task bars by up to 5px inside every group, and the timeline widths are formatted with the invariant culture so cultures with a comma decimal separator no longer produce invalid CSS such as width:81,48px (#2801). Thanks to @ewerton336!