I’ve also run into this. It seems like it also prevents me from joining into a strike team/being able to start a mission. I’ve restarted my game several times and still run into this.
EDIT: Found a similar reported issue here: The match does not start due to an error and can't be cancelled during search
EDIT 2: Looks like this is awknowledged/being worked on from a post in tech support: Matchmaking is taking forever - or empty_ticket error