How to Delete a Materials Language
If you are not familiar with the concept of materials language, read the article Managing Available Material Languages first.
Switch to the brand's account of and select Account Settings in the top second-level menu.
Find the language and click Delete link
When you delete a language, it disappears from the event form. No new workshop can be created with the removed language. However, the removal of the language doesn’t modify existing events.
If you want to remove all materials languages at once, click Deactivate button.