The site on Bitrix is ​​broken, what happened to it?

Question

1C-Bitrix

Good afternoon!
Our company's site on Bitrix "broke":
All the design has fallen off, the pictures are partially shown, distorted or completely absent.
A week ago everything was fine, no changes were made there.
Configuration:
1C-Bitrix Site Management 14.0.5, PHP 5.3.29, MySQL 5.5.52. The license has not been renewed since November 2013 - "The site is working, but we don't need more."
The most interesting thing is that I had a working backup on a virtual machine, I made changes on this virtual machine, and only after the "break-in" did I update the hoster's website. On the virtual machine, the site is also broken! Although more than a month has not run this virtual machine. I checked on all browsers I have installed, with extensions disabled and in incognito mode. I walked through the offices in search of computers with outdated browsers - the site does not work normally anywhere.
Could it be that this happened due to an expired license? There is also an idea to check the performance of the site on a virtual machine with a date set somewhere at the beginning of 2018.
I noticed another "strange" phenomenon - today Adblock Plus "broke" Yandex, pictures and other things were not shown in the same way (therefore, I checked "my" site with all extensions disabled, reset browsers to "factory" settings). Maybe I missed some global update of the web servers or something else?

Answer 1

Something is wrong with the engine. The part that loads styles and scripts on the open page shows that it is commented out

<!--?
require($_SERVER["DOCUMENT_ROOT"]."/bitrix/header.php");
$APPLICATION--->

Although there are no comments in index.php
Problem solved! The template on the hosting flew off, copied from the virtual machine "Settings-Product Settings-Sites-Site Templates"

Answer 2

As already said - this is 100% not a license.
The first thing to do is look for errors in the console.
It could break because of the underload of some resources. There are thousands of options here.
From the CDN (which must be turned off as already mentioned) to the fact that you were collecting css on the client side with some js library, say from less files, and this library was loaded from a third-party site, which is now unavailable.
You can’t just say why this happened, but I bet on the unavailability of an external resource, since “The site also broke on the virtual machine!”.
Check for errors in console.

Answer 3

Disable all available accelerators.
CDN, CSS and JS compression, composite (if there was one then), clear the cache.
Should help.