If you have EZPESU-2014-006-EZOE5.5 applied, you won't be able to upload and embed images from a XML Block.
In Firefox, the browser will hang and there will be no noticeable error. In Chrome you will get the following error message: Uncaught SyntaxError: Unexpected identifier
It's also possible that this update generates a SyntaxError: Unexpected token ILLEGAL 1:1" as well.
- Apply the patch
- Edit or create a new content object
- Try to upload an image from a XML attribute