Sorry, the readme file did NOT say this. We did add a couple items in the upgrade instructions for this release, but missed this one. However, it WAS mentioned in the release news article AND in the email newsletter that went out.
Anyway, there is no bug here. It's strictly a permissions setup. As isaiah said, you should not have "Edit Own Event Only" checked. In 99% of situations, this should not be checked for Super Users... and it is not checked by default. If you give yourself access now to manage records, but have that box checked, you will only see records for events that you are the named owner of.
If you have Manage Records checked... and do NOT have the edit own event checked... but you still do not see records... then check your user group assignments of the account you are logged in with. Maybe you are assigned to multiple groups... including one that does not have access. Either way, it's a permissions setup issue to sort out on your site.
You can always add your user to the permissions matrix to give permissions directly to YOU regardless of any other user group associations with your username.
"You can always add your user to the permissions matrix to give permissions directly to YOU regardless of any other user group associations with your username."
I tried this - and I can see the records now. I created the superuser as a user.
BUT it does not work with the default settings.
This arrangement is going to be very confusing for novices.
I discovered that I had one login that was both superuser and registered. Only superuser permission set to view records. When I logged in with that user name, I could not see the records, so the "registered" category permissions were superseding the superuser permission. Fixed by removing the "registered" category and left it only superuser.
I'm getting the same problem here... after updating to 2.8 the records are gone. Permissions were all set and resaved after upgrade. Records are only viewable if individual users are added to the permissions list and permissions granted to them. This is getting around the problem, but is not as convenient. Why are the user group permissions not working?
Same problem for me in 2.8.1. Checked all suggestions above. Am a Super User (no other group checked) with correct permissions (all checked except edit own event only) but cannot see backend records for events that have another user assigned. Solved if I add myself as a specific user with exactly the same permissions as the super user but indicates something is still wrong.