Compiler can't find ItemArgs

[utahman]

While compiling Assets\Battlehub\RTEditor\Runtime\RTEditor\Legacy\Dialogs\AssetLibrarySelectDialog.cs
it says it can't find what is ItemArgs in this line:
private void OnItemDoubleClick(object sender, ItemArgs e)

The definition of ItemArgs is in:
Assets\Battlehub\UIControls\Scripts\ItemsControl.cs
public class ItemArgs : EventArgs

And that is only one error out of 115.
Using version 4.5.1 from Dec 18, 2024