Tickets went on sale yesterday for Oogie Boogie Bash (June 29) and many were stuck in queue for more than 6 hours only to be told they would have to try again on July 6th.
So if you were one unlucky yesterday, you still have another chance!
I also wanted to share how I was able to get my tickets, in case there's an issue again. I was stuck in queue on my computer, but was able to get tickets on my phone.
All I did was take my phone off of wifi, go to the Disneyland app, go to special events, clicked Oogie Boogie Tickets and it did send me to queue a few times, but I kept trying since it was allowing me to select tickets and after maybe the 6th try it pushed me right through and I was able to secure my tickets.
Good luck and I hope this helps!