Base64 in CSS files on SharePoint 2010 is being truncated

First message, long-time lurker. Hoping that someone will have an answer to this quirk. I've searched for Reddit, Stack Exchange and Google without any luck.

I have a very strange problem with SharePoint …

My company runs a SharePoint 2010 Server with an Enterprise Client Access License, an on-premises server farm, which no longer has a support agreement, so no direct help from Microsoft. In addition, the IT department does not have much experience with SharePoint.

We rely on the ability to download HTML 5 content produced by various sites (Articulate, VisMe, etc.) and tools (Camtasia) for viewing by an audience without access to the Internet (otherwise we would host simply the online content). . These tools contain Base64 encoded elements found in the code they generate, especially in .html and .css files. The coded elements were all PNGs, SVGs or fonts and were in the src or url part of an attribute.

Example:

.selector {
background-image: url (data: image / svg + xml; base64, datahere = & # 39;);
font family: 'Lato Bold'; src: url (data: application / font-woff; base64, datahere =);
background: url ("data: image / png; base64, datahere");
}

The files will be downloaded correctly and will work perfectly for everyone. However, at what appears to be a random interval, the content encoded in Base64 in the files is truncated. The amount of truncation is exactly the same each time it occurs in a file. This happened for the first time with some files about a year ago. After a few days of rewriting the files, the problem was stopped. We therefore assumed that the problem was solved.

Since the files are stored in the SharePoint database, we know that the Windows 2008 server antivirus is not truncated and that the built-in SharePoint Server antivirus is disabled. The problem occurs when the content is stored in a list or document library. Two identical files can be in the same document library, in different folders, and only one copy will be assigned.

The version of the file does not change and the audit logs do not indicate any changes to the files. Modified will be empty or will display my name if I have overwritten the file to fix it.

Does anyone have an idea of ​​why this is happening and hopefully a solution?

Thank you very much for any help!