The visual composer failed to work. I discovered that WP was up to date, but Salient was at version 4.1.1. I successfully updated Salient, installed the bundled VC and it's working again.

However, now my website isn't working anymore but spinning indefinitely. Console reports:

JQMIGRATE: Migrate is installed, version 1.4.1

init.js?ver=7.6:6244 Uncaught TypeError: Modernizr.prefixed is not a function
    at $.DLMenu._init (init.js?ver=7.6:6244)
    at $.DLMenu (init.js?ver=7.6:6207)
    at HTMLDivElement.<anonymous> (init.js?ver=7.6:6462)
    at Function.each (jquery.js?ver=1.12.4:2)
    at a.fn.init.each (jquery.js?ver=1.12.4:2)
    at a.fn.init.$.fn.dlmenu (init.js?ver=7.6:6456)
    at fullscreenMenuInit (init.js?ver=7.6:6475)
    at HTMLDocument.<anonymous> (init.js?ver=7.6:6532)
    at i (jquery.js?ver=1.12.4:2)
    at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4:2)

This is especially unfortunate as I just launched a campaign to drive traffic.
Please advise at your earliest convenience.

My server uses

PHP 5.6.26 / 7.0.3

MySQL 5.5

Perl 5.20.2

Thank you! It seemed that "GZip Ninja Speed Compression" was at fault. I also used an online form plugin of the same developer, equally outdated. Did you bundle/recommend "Contact From 7" or "Fast Secure Contact Form"? - So I can rebuild that reliably.

I will keep an eye on the compatibility of plugins in the future.

The only other loss in the process seem to be the widgets in the footer area. Those are actually outside of Salient, true? Did they get flushed due to the Wordpress update? I don't think they were connected to a plugin.

Now my problem is that without the GZip Ninja Speed Compression plugin my 100+ portfolio items each load extremely slowly, 20 seconds and longer! I'm not sure why. There is a header image that should be cashed, maybe 3 thumbnails for related projects, and the rest is an embedded vimeo player. What do you recommend for optimization? - Thanks in advance.

Thank you, I managed to get it up to speed!

Simon