When creating or editing an item, the controlled vocabulary for a field is not shown in the popup window.
The error written to the log is a NullPointerException in the method transformDocumentAsString of XMLUtil class (line 166). Also the error contains the next message: "vocabulary2html.xsl:1:1: Content is not allowed in prolog".
This problem only happens when the path to the xsl file contains the pound symbol (#), because a StreamSource cannot be instantiated passing a string as a parameter containing this character.
I find a workaround to fix this problem: instantiate a FileInputStream with the path (String) of the xsl file and then create the StreamSource passing that instance.
Hope this helps.