"Not a valid image" error when filename includes an ampersand

[G80]

Uploaded image's filename can't include an ampersand or you'll get an error "Not a valid image".
Confusing, started to look what's a valid images then.

[Zegnat]

Did you file this against the wrong repository? You cannot upload to this cheat sheet. Or can favicons never be given a name including an ampersand when provided through META tags?

[G80]

I'm sorry, found Github link on front page and thought automatically it's Favic-o-matic's. Wrong repo.
But is there a repo for Favic-o-matic?
This is issue can be closed.

[Zegnat]

But is there a repo for Favic-o-matic?

Not that I know of. There is an email address (feedback at favicomatic.com) and twitter (@favicomatic), but that’s it.