Uploaded images can not be displayed

[JavonX]

Hello there

I stumbeled on an problem that keeps recurring infrequently. And I can not reproduce it.

Sometimes when I try to upload images to an image-field (set to array), the upload itself works but the picture won't be displayed on the edit page. The name and dimensions of the image are correct, but the preview is just white. When I click on it for full-size I get the error

"This image could not be loaded"

When I click on the "This image" link I get a server error: "404 this file or directory could not be found".

The file is properly uploaded and not corrupt. On the web server I can navigate to the asset file folder of that page and open the image in a browser. It's not a problem with the file itself. It happened with svgs, jpg and png of various dimensions and filesizes.

It happened sometimes with the first file i tried to upload with it. The first time, it happended on a page where I already uploaded 10 pictures.

Once the error occured this happens to any picture I try to upload on that page. When I click on "view" to see the php-page i get the same 404 error.

Any idea what's going on? Is something corrupting a MySQL entry?

I'm running ProcessWire 2.6.1 on a IIS Server