When I create a new Content Template configuration an error occured

• right click on Content templates
• fill extension id (test for instance), and what ever target document type
• remove the default values (for root, I remove default domain), the root is not selected
• I click on add
  => error (see below)

The error message is not really clean, we can't click on ok.

(TypeError): Result of expression 'e' [null] is not an object. line: 5255 sourceId: 5199729520 sourceURL: https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/A48589A7ABFBEE6BCC323D2D24F6EEE9.cache.html expressionBeginOffset: 426 expressionCaretOffset: 427 expressionEndOffset: 430
Details
Uncaught exception: com.google.gwt.core.client.JavaScriptException: (TypeError): Result of expression 'e' [null] is not an object.
line: 5255
sourceId: 5199729520
sourceURL: https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/A48589A7ABFBEE6BCC323D2D24F6EEE9.cache.html
expressionBeginOffset: 426
expressionCaretOffset: 427
expressionEndOffset: 430