Sharepoint in Explorer-View can't display images “because the file is empty”

I am administrating a SQL Server 2014 for our Sharepoint 2013.
Currently users are facing the following issue:

Using the Explorer View, some images randomly (at least I can’t find a pattern until now) are not displayed because “the file is empty”. So I don’t even see a preview / thumbnail. If I expand the files properties the image size displays 0,0 KB. Clicking a second time or copy that image to another location, sometimes makes the picture visible. Keeping the session open, later on it might happen that the same image is gone again. Out of 100 images in a folder, a couple can’t be displayed at the very first attempt.

But by clicking the properties or trying to copy that file – in the end every single image is visible. So I never found an image which was really 0,00KB.

I have no Idea how this problem can be solved since I have no clue where this is coming from.

I am using Internet Explorer 11 and run Windows 7 on my machine while the server is 2012 R2 with SQL Server 2014 and Sharepoint 2013.

EDIT 29.02.2016
It affects all files, not only images. Also saved emails can be empty. Meaning 0,00 KB in size.