Gist contains binary

[Trulsaa]

When pressing enter or o on a gist in the gist-listing buffer I get the "Gist contains binary" error. This applies to public, secret and anonymous gists.

Has anyone seen this issue before?

[jinmiaoluo]

Same error.
Neovim version: 0.3.7
Gist.vim version: commit 3abf244
What did I do:

vim test.txt
add some text and upload it
:Gist
open browser automatically
return to Neovim
:Gist -l
find the gist with the same name
press enter
can't get the gist with an error 

my Neovim config:

...
Plug 'mattn/gist-vim' | Plug 'mattn/webapi-vim'
...
let g:gist_open_browser_after_post = 1
let g:gist_show_privates = 1