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 account of the brand’s coordinator and select Account Settings -> Settings.
In the module Materials' Language, find the language and click the 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 the Deactivate button.