Bug report

Scenario 1: When you first select an invalid file and then a valid one, the upload button appears but does nothing.

Scenario 2: When you select a valid file and then an invalid one, if you hit the upload button, the widget will try to upload the invalid one and produce a server error.

Reproduction of the problem

Scenario 1

1. Open this demo - https://demos.telerik.com/kendo-ui/upload/index
2. Select a .PNG or another invalid file.
3. Select a PDF ( or another valid file)

Scenario 2

1. Open this Demo - https://demos.telerik.com/kendo-ui/upload/index
2. Select a PDF ( or another valid file)
3. Select a PNG ( or another invalid file)
4. Press Upload button

Current behavior

Scenario 1
The Button appears but does nothing

Scenario 2
The widget attempts to Upload the invalid file and produces an error

Expected/desired behavior

Upload of invalid files shouldn't occur and no errors should be thrown;
A non-responding Upload button shouldn't appear.

Environment

• Kendo UI version: 2022.3.913
• Browser: [all]