https://addons.mozilla.org/en-US/firefox/addon/zotero/ uses e4x and is broken by bug 788290. We need to reach out to them....

bz: are you certain the latest Zotero still has this problem? I went to their website and they said "The version of Zotero you have is not compatible with Firefox 17. Download version 3.0.10". And I did. And it seems to work now. (I foolishly didn't check how well it was working before upgrading, although I'm sure I've used it recently.) 17 is the first version with E4X turned off, so it seems plausible that their upgrade request and this issue are connected. Is there some particular bit of Zotero which you know uses E4X which I should check? Gerv

> bz: are you certain the latest Zotero still has this problem? The version I tested is 3.0.8, which is what's on AMO. I don't know about 3.0.10... > 17 is the first version with E4X turned off 17 has e4x turned off for web pages. e4x for chrome got turned off on mozilla-central this morning. When I started a self-build from yesterday evening (pulled from inbound, so already had the change to turn off e4x for chrome), there were tons of errors in the error console from Zotero code using the ".@" property accessor syntax from e4x, and it didn't actually run on the file:// URIs I was loading (as evidenced by them not crashing even though that other crash bug I was debugging was still present). So if you use a nightly from today, or maybe from tomorrow depending on when the merge to m-c happened this morning, and start with Zotero, just check your error console...

Version 3.0.11 is awaiting review on AMO.

It looks like 3.0.11 still makes extensive use of E4X. I sent the developers a message via AMO warning them of its removal.

e4x support is now gone on mozilla-central (bug 788293).

Thanks—we've been working to remove Zotero's E4X for a while, and we removed the last of it earlier this month on our main development branch. We'll have a release out from that branch by the time Firefox 20 is out. (There'll be a beta available from zotero.org sooner, and people running Fx20+ can use our dev builds in the meantime.) We had to make a lot of changes for Firefox 17, hence the upgrade message that Gerv saw, but that was mostly unrelated to E4X.

This is fixed by now, as testing shows.