plug-in for Word stopped responding
I've been using Zotero with Word for many months, and it just recently stopped working. In Word, I can click on any of the Zotero options in the "Add-in" menu, but none of them do anything. Word itself still works fine, just not Zotero.
http://www.zotero.org/support/word_processor_plugin_troubleshooting#zotero_toolbar_doesn_t_appear
If they don't help, see if you can provide an error report ID from the gears menu in Zotero.
If you did w/o success - which OS and Word version?