ah, i find why error occur.

https://steemit.com/news/@kubrickkk/missing-posting-authority

Just had the Same issue, it was a special architecture hidden as a space.

Solution

Copy your text, go here:

https://www.textmagic.com/free-tools/unicode-detector

Paste your text and look for the RED blocks.

Go edit out the red out of your post, you should be ok!

it's a special character include in your post or title, or image's title.