I am developing a multisite that is not live yet. Most of the sites are running The Core theme (some child version of) from Themefuse. I have just upgraded to WP v 4.8.2, Core v 1.0.25 and Unyson v 2.7.7. My sites lost the css associated with the theme and I asked them for support. The result was a corrupt .htaccess file in wp-content/uploads. (I'd gone through the process of turning off all plugins and then deleting the htaccess file). All seemed to be good when I reset everything, but next time I logged in it was gone again. I have now narrowed this down to Memberhip 2 Pro putting that file there (it reappears shortly after me deleting it). I have just updated Membership 2 Pro (v1.1.1) hoping that would solve the problem, but it hasn't. With Membership 2 Pro not active, my site is fine. I will need Memberhip 2 Pro working for some of my sites before they can go live.