git-annex add . fails with:
git-annex: unknown response from git cat-file ("HEAD:./MYDIRECTORYNAME/Icon missing","HEAD:./MYDIRECTORYNAME/Icon\r")
There's a file in the directory called IconM or Icon? (there's some kind of control character or unicode or other weirdness at the end)
It looks like you had a newline in your filename. Which is very unusual.
git-annex actually got support for those in version 6.20180913.