Pictures with orientation module have a black thumbnail

Has anyone seen this before? Bug or user error?

Pictures, which are turned by 90° with the orientation module are displayed with black thumbnails. Looks like this:


The last one should be turned, but I deactivated the orientation module, and it is displayed correct.

The activated modules on one of the images with black thumbnail are as follows:

So, really nothing special, as far as I can tell.

Looks like a bug to me, which probably should be reported?

Ah yes … this is a nightly windows build:

I have recognized the behavior for about 1-2 weeks, I would say.