IF you have "server error 500" Crash on your site!
It's because of "Disable PHP in Uploads" tweak crashing the site after last update!
Just comment related string with sign "#" in .htaccess file! and your site will be online again!
After that you need to disable tweak named "Disable PHP in Uploads" in - iThemes Security - Settings - System Tweaks - Uploads.
And wait for new update, where this bug will be fixed.
P.S.:
Hey, admins! We are waiting for fix!