Failed to create connection: Feed URL doesn't appear valid

[bkil]

If the feed URL contains a question mark, ampersand and equals sign, it fails to subscribe.

The request failed with HTTP 400 with the following body:

{"errcode":"HS_BAD_VALUE","error":"Feed URL doesn't appear valid"}

[bkil]

After retrying in a few rooms, it turned into the well known error Failed to create connection: Could not read feed from URL: error sending request for url (...): operation timed out Must be a glitch and otherwise a duplicate of #765