Test reply because @chrisaldrich was getting an error. Might be OK with reply but not webmention, so will test that next.

It can be so hard to debug IndieWeb problems when they arise in Known. For now, this should be a webmention of the linked post, because Chris Aldrich reported a problem. But even if this works, I may need to go outside this installation to test properly. Or, perhaps, try webmention.rocks.

Sometimes, a man's gotta do what a man's gotta do.
Like send a webmention to himself. Because someone else was getting an error when they tried to send one.
And then, maybe, I can try using Telegraph to resend Chris' original.