Comment 3 for bug 571369

Looks like theres a problem getting the name from the button, causing the dictionary search name to return null, this is fixed in version 1.3 with much tidying up of the way this is done.
Note, to work around this you can install/uninstall dictionaries via the command line.
For example,
$ waei -i
Installable: English Kanji Radicals Names Examples French German Spanish

$ waei -i French
Trying to install French...
* Downloading file...