Curse.com and WoWInterface.com, two of the biggest add-on repositories, have banded together to block third-party add-on manager program WoWMatrix from being able to grab data and add-ons from their web sites.
A news release from Curse clarifies that this is due to Curse's bandwidth being used while WoWMatrix profits by having its own advertising on its client. In addition, Curse claims that authors have not been asked permission to have their add-ons included and WoWMatrix has been unresponsive to requests to have add-ons removed from its database.
What does this mean to you? It means that you can no longer use WoWMatrix to update add-ons that are hosted at Curse or WoWInterface, which is quite a lot of them, including GuildEventManager (GEM). Both Curse and WoWInterface have their own client programs which, naturally, only work with their own web sites. Curse clients are available for Max OS X (10.5+ preferably) and Windows.
Elsheindra
It's weird that there's nothing on WoWMatrix's site about this. Maybe they hope to somehow resolve it amicably or just work around it?
I have just tried again and updated gatherer, questhelper, cartographer etc. so seems to be fixed now