We have crosslisted courses set to "Meta course" and we had "Place users in merged courses into groups" set to "Yes." The former was changed from merged, the second is default behavior. We're running the June 7 release. We've had this in production for close to a month. Starting recently, folder processing failed with the message "Can not find data record in database table groups." Setting "Place users in merged courses into groups" to "No" (which, on reflection, makes no difference in our case) resolved the issue.