In both Edge and Firefox in Windows, clicking on a post to open in the kinda/sorta popup window loads, but “Oops something went wrong” instead of loading comments. I’ve turned off my ad blocker(s), no change. I don’t have any other extensions that would interfere.
If I specifically open in a new tab, they load fine.
Just started today with no changes on my end.
I see this behavior when I use RES to change from one Reddit profile to another in different tabs for the same instance of Firefox. Restarting the browser clears this out.
Are you changing profiles while different Reddit tabs are open by any chance?
Just the one login. And multiple browsers affected.
Erroneous behavior confirmed by a few others, one of whom pointed me to https://www.redditstatus.com/ which confirmed the issue on the system side.