TIFF file not recognized
The attached 1px.tif cannot be opened with GIMP [Opening 'D:\temp\1px.tif' failed: TIFF'D:\temp\1px.tif' does not contain any directories] It comes from https://github.com/mathiasbynens/small and opens OK with Paint, Irfanview, Firefox, Palemoon.
Obviously extreme borderline case, but nevertheless...