Fixed JS error while rebuilding caches?

[Oblivion Knight]

Just tried updating a modification (from server), and received a javascript error whilst XenForo was rebuilding caches.

It got to Email Templates, and I received this;

Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; Zune 4.7)
Timestamp: Wed, 9 Mar 2011 10:44:34 UTC

Message: The data necessary to complete this operation is not yet available.
Line: 104
Char: 4
Code: 0
URI: http://www.gamingvoice.co.uk/forums/js/xenforo/cache_rebuild.js?_v=3cd86e19

I'm not sure if it's a bug, or just my host having a silly moment..

[EDIT]
I've just tried it a second time and it didn't get the error, so I would guess the latter.

 

[Mike]

I've never seen this reported before, but doing some Googling indicates that the error function (where that line points to) must've been called without a server response. It looks like we should be able to check the readyState as well, which I think should prevent this from happening.