i'm sorry, i have no idea why but i've seen a couple others with the issue and i dont know the first thing about linux, i just used rpg maker mv's default export for linux option.. my sister uses linux as well so i'll see if the two of us can figure it out soon
should work now. the issue is rpg maker uses an outdated version of nw.js that doesn't work with modern linux. updating nw.js should fix this hopefully, but it's possible some things might be broken. i haven't been able to test it on linux myself yet :/
edit: there might be a mistake with the text box being green... i'll try and get it fixed tomorrow but otherwise i also started hosting a web version on my site and that should work on any OS :)