Document type can be edited by multiple users at the same time

• open cms in one browser (e.g. firefox)
• go and edit a document type

• open cms in another browser (e.g. IE), login as a different user
• go and edit the same document type

• add a string field in browser 1
• add a string field in browser 2
• save in browser 1
• save in browser 2
• you get an error message that path string is already in use (which is true because it was added through browser 1, but browser 2's user doesn't know this)

Who knows what other unpredictable behavior this could have as a result.

Probably, like editing a document, editing a document type should be disabled when a type is already being edited.