Broken wordpress editor

I have a problem – I have a website on the Avada theme. When I install WP-Tiles my wordpress editor is broken. It is sht like this: http://pudelka-zapalek.pl/wp-content/uploads/2016/09/wp-tiles-broken.bmp

I used this plugin on the another website with Avada and it was ok. What shoul I do to fix this?