Hmm true, leaderboards seems to be broken even with a completely blank save. There must be some weird score submission there preventing it from loading. That should be unrelated to your blank enemies bug though. There must be something still broken in the save if it keeps loading the same glitchy enemies every time. Try clearing the EnemyBones_something key too...
Okay so most of the time just Alt+F4ing and rebooting the game works to refresh the enemies, at least at low levels. I haven't yet tried clearing the EnemyBones_whatever key (it actually doesnt exist at the time of writing on the new save I'm on right now), but what I assume is that the EnemyBones_whatever key is the one that stores the enemies, and when they're randomly generated there's a chance for them to bug out and return a nothing? So not having an EnemyBones_ key in my registry right now suggests the deletion fix works. I'd have to get back to you on that one until I get to high enough of a level to encounter players though (iirc around level 50?)
I have also encountered the no items in shop bug that @potatobirb mentioned below. Rebooting in this case does not seem to fix the issue so I'm not sure what to clear. I don't see a value here that might store the shop's items, and I presume it randomly generates it based off of a predetermined seed every hour, since it refreshes even when offline.
Edit: Deleting the EnemyBones_ key did in fact fix the blank enemies bug :D
However, even after deleting the entire branch, the shop is nowhere to be found...
76 days ago(+1)
The leaderboards thing is now fixed. The issue was not actually on your end but my server service provider (which was migrated from another provider) had some strict firewall setting on and blocked all web requests from non-browser apps. For the empty shop I'll have to do some investigations but it seems like normally it works but there can be some items appearing which make it not work...