The command CSS Style Builder does not exist anymore on any ribbon or toolbar or in any menu since UltraEdit for Windows v2022.0.0.70 (29.0.0.70) as I just found out although the help contains still the page Style builder command (Coding tab) about this dialog window referenced on the help page Coding Tab. The command is also not available anymore in the ribbon or toolbar customization window. The command with its symbol is still in the Tools toolbar in my custom layout as I have not reset the Tools toolbar since a long time to the defaults. The Style Builder dialog window can be still opened by me by clicking on its symbol in the Tools toolbar of my custom layout. But it is not possible anymore to add it to this toolbar as not listed anymore in the commands list of the toolbar customization dialog window.

I suppose that the CSS Style Builder was removed as being obsolete in the meantime because of CSS2 has been replaced by CSS3. The Style Builder dialog window can be still used in UltraEdit for Windows v2024.1.0.36 by assigning a hotkey or chord (multi-key assignment) to the command Style builder at Advanced - Settings or Configuration - Key mapping. Pressing the assigned hotkey or the keys of the assigned chord opens the Style Builder dialog window.

I asked support of UltraEdit, Inc. by email and here is the short reply:

UE support wrote:There aren't any specific plans to replace the CSS Style Builder at this time, but it may be updated in the future. I have logged this as an enhancement request.