“Just to give everyone an update, we will not be enabling any additional events this weekend while we concentrate on implementing fixes for the Activity Finder. When we dug into why the issues began yesterday, we uncovered a new problem where certain groups queuing with the Activity Finder were causing significant database load issues. The fixes we’re working on will better distribute the load and impact on the database, and they are currently with QA for testing.”
Once ZeniMax Online Studios has the results from QA testing, we can all expect an update this coming Monday. For the time being, though, you’re going to have to go without the Activity Finder or any weekend events.
source: official forums