PDF - Unexpected response from the server

Hello, for a few days now I have noticed that when I upload a PDF to the media library, I get the following error: “Unexpected response from the server. The file may have been uploaded correctly. Check the media library or reload the page.” I refresh and the uploaded file appears and its link works, etc., etc.
If what I upload is an image, there is no problem at all, and the PDF is small in size.
Could it be a bug in a plugin or in WP itself?

Thanks in advance.

 

No es por el tamaño, tengo mi propio servidor y tengo la gestión completa, los parámetros PHP son correctos, puedo subir imágenes grandes, etc. El problema es con los PDF y es algo repentino que no me pasaba hace unos días. De todas formas, miraré el enlace facilitado.

Gracias

 

It's not because of the size, I have my own server and I have full management, the PHP parameters are correct, I can upload large images, etc. The problem is with PDFs and it's something sudden that didn't happen to me a few days ago. Anyway, I'll look at the link provided.

I'm putting some images of the process of the problem in a random place of my WP.

img_1
Uploaded a 38Kb pdf and the commented error notice.

img_2
Once the browser is updated, the pdf is displayed perfectly.

img_3
If you click on it, all the properties are good, except that it loses the pdf preview icon.

img_4
Uploading any image of about 8Mb works perfectly and as you can see, I have the size limit at 64Mb.

Greetings

 

It's nothing like what the link provided says
I uploaded the pdf that you provided me and it does the same thing, it's not something with the text sources, I even generated a blank pdf with nothing and it does the same thing. It gives the error message, I update and the pdf appears (without preview) and it works without problem. I even deactivated all the plugins to look for some incompatibility and nothing, the same thing. I tried the same thing in WP that I have without Divi and it also does the same thing.

I'm afraid it's a WP problem or my server due to some update or something similar, I don't know, I'll keep investigating.

Thanks