In similar to EZP-27512, when we set a space/tab/any other white character as a content type identifier, the following error is raised

Failed to load 'http://192.168.56.102/pjax/contenttype/update/2/eng-GB'

instead of regular validation error message.

Steps to reproduce

1. Create a new content type
2. Set the identifier as a space
3. Save the content type
4. Notification contains text

Failed to load 'http://192.168.56.102/pjax/contenttype/update/2/eng-GB'

instead of a regular validation error message. Error labels aren't displayed under form fields.