When trying to upload some of the per-language indices I have generated locally, I get a null response from the server, there doesn't seem to be an error message, just a blank screen. (I've been trying to save the text at http://www.mediawiki.org/w/index.php?title=Sandbox&action=edit&oldid=191322 to http://en.wiktionary.org/wiki/Index:English/a )
Also, when trying to view some of the indices I have managed to upload I get a null response from the server, ( http://en.wiktionary.org/wiki/Index:English/b ). It is interesting to note that some people are able to see the history of the page, and some are able to see a purged version of the page, however this seems intermittent.
Most of the pages similar to this are fine and work properly ( http://en.wiktionary.org/wiki/Index:English/s ).