@minouchka123 said:

It did work but now I have Lib Fredo [v12.8(a)] and the SketchUcation Toolset [v4.2.6 or 7] and round corners is just not appearing in my tools anymore, it appears on the extension manager but not in my tools.

Could you upgrade to

LibFredo6 v13.8a Sketchucation ExtensionStore v4.3.0

There are chances that it resolves the problem.