Last modified: 2013-10-31 12:08:32 UTC
It could just be stale js, although I get this with debug=true also.... I get "Cannot read property 'length' of null" when trying to add or edit aliases on wikidata.org problem is in toolbar.js on line 294 called from wikibase.ui.PropertyEditTool.EditableValue.js line 1073 in case anyone else has this issue...
It works for me when adding an alias to the sandbox item.
Can you please check if the error still exists since I am unable to reproduce.
assume this is okay now.