loading failed for the … etc

Hi there,

Is that on Google Chrome or Firefox.

If it’s Firefox, take a look at this: https://stackoverflow.com/questions/45879671/only-on-firefox-loading-failed-for-the-script-with-source

If it’s on Chrome, I’ll need a bit more info on that.
Do the .js files open if you copy paste the .js urls in your browser directly?

If they don’t, it could be file permissions on the server.
Check that your wp-content/uploads directory has write permissions and is owned by the correct username, then purge FVM cache.

FVM will replicate the file permissions of the uploads directory.

Can you try the latest update and see if it works?

If it doesn’t, can you save a copy of your frontend html (save as html from your browser, as logged out user) and send it to me? I need to evaluate if there is something wrong with how FVM is merging the js files in the html code.

You are the only person complaining about this, so I am inclined to say it’s something related to your server, which may have changed around the time you updated.

Furthermore, accessing your site shows an error:
http://prntscr.com/me7mn2

Anyway, looking at the error messages on the log you attached, it says:

header-ceb60cc1-1548416754.min.js:1 Failed to load resource: the server responded with a status of 404 ()

This “should only happen” if you purged the FVM cache files without purging your page cache. That page cache can be from a plugin you use, or something on the server side.
I would suggest, for your server to select the option to preserve cache files on FVM settings.

HOWEVER, further down I see references to rocket-loader.min.js which if I am not wrong, comes from cloudflare.

Auto Minify, Mirage and Rocket Loader must be disabled at the Speed tab, on Cloudflare.

Not only those options slow down your site (even without FVM), but they are know to cause conflicts in many websites.

Mirage for example, states:

Mirage is considered Beta because it’s an experimental feature that may cause issues displaying images in association with certain Javascript libraries, such as image carousels or photo viewers. Issues with Mirage affect only a small percentage of customers.

HTML Minify option will cause doing double minification, which can cause conflicts. Double minification, should not occur under any circumstances, ever.
If FVM is already doing it, you are slowing down the site by doing it yet again on cloudflare.

Rocket Loader is a pure scam too. On all the sites I have tried to use it, it slowed down the execution time for mobile users.

I love cloudflare and I use them extensively with hundreds of sites, but I don’t know what cloudflare was thinking when they came out with this option. Using more javascript, to speed up slow javascript… just doesn’t make sense.

Disable those settings and purge all caches, server, fvm and cloudflare.