To delete Knowledge content, make sure that the status of the content is inactive. The steps to do it are described in this article.
To delete a piece of Knowledge Content:
2. On the left side panel select the application you plan to work with. The application menu opens.
3. In the Application menu go to Manage > Knowledge Center. The list of materials added to the Knowledge Center via Launchers or through Admin Console opens.
4. Find a row with a piece of content you are attempting to delete, click the (three vertical dots) button at the end of the row and select Delete in the context menu. If Delete option is unavailable as shown on the screen below, from the context menu select Edit. The Edit Knowledge Content screen opens. Make this piece of content inactive by clearing the Active checkbox. Return to step 4.