Subscribe to feed gives error “Sorry, an error occurred”
This happens for both the admin user and at least one poweruser account.
There are no entries in the system log when this happens.
This has been going on for a while but I just got around to posting a question about it. My current workaround is to pick my least favourite existing feed and edit it, which works. It also keeps my list short, but I am running out of least favourite feeds to cannibalize…
Solution: I had AdBlock Plus (ABP) running, and it broke adding a feed. Disabling it for this page fixed the problem.