Bug report

Reproduction of the problem

1. Go to the Themebuilder page
2. Select BlueOpal theme
3. Modify the "Error" color.
4. Download the custom theme

Current behavior

The generated kendo.custom.css file contains the following rule:

undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined .k-text-error {
  color: #7030a0;
}

Expected/desired behavior

The rule should have correct selector, or if it is redundant it should not be included in the file.

Environment

• Kendo UI version: 2020.2.617
• jQuery version: x.y
• Browser: [all]

I have a Bootstrap or Material based theme created from the ThemeBuilder. When I add it to my application I have noticed that the ShowInEdit property of the GridCommandButtons does not work as expected. 

<AdminEdit>

This is due to the lack of the k-hidden class. In order to solve the issue, you could add the following CSS rule to your <filename>.css file.

CSS:

    .k-hidden {
        display: none;
    }

</AdminEdit>

On creating a custom theme based on the Default v2 theme (its possibly the same with the other SASS themes), if you uncheck a component (e.g., the Editor) in the list so that the modifications do not apply to it, the ResponsivePanel does not work as expected with the created custom theme. On narrow browser window width, the sandwich button appears, but the Menu wrapped by the ResponsivePanel does not hide.

To reproduce:

1. Go to the SASS Theme builder.
2. Select Default theme.
3. Uncheck the Editor from the list.
4. Change a random variable and download the theme.
5. Load the custom theme in a new Telerik UI for ASP.NET Core application created with our VS template. The template has a ResponsivePanel set up by default in the _Layout.
6. Run the project and resize the browser window so that the sandwich button appears.

Expected: the Menu wrapped by the ResponsivePanel hides.

Actual: The Menu remains visible.