The mentioned translated resource is a custom one and not officially supported by Telerik. Issues and problems related to them should be handled as per to the case and by the developer of the application.
The tools in the context menus are actually the same tools located into the toolbar and the names are the same as set in the toolbar.
The RadEditor can fall back to default labels, although if the corresponding labels have been set to empty strings, they are considered as strings and cannot be detected as null or undefined.
I suggest comparing the used localization files with the ones officially provided in the Telerik UI for ASP.NET AJAX suite and modify the labels as per to your needs.
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