In case of mess in your editor window, just add this line to your .vimrc:

let g:ale_virtualtext_cursor = 'disabled'

A mess in VIM (look at these red inline error messages)

The root cause of the issue

Some idiot creative guys thought that mixing warning messages with code makes some sense and increases readability, and someone smart enough implemented it (to the misfortune of mankind).

A source of the mess in vim

The other one great dev enabled the mess at default (dunno why, maybe he thinks that mess in the editor window is so awesome):

An awesome idea of enabling mess in the VIM editor at default