With Luminance-hdr 2.3.0, I wasn't able to open some EXR files generated with recent Hugin versions.
I got an error like "ERROR: Failed loading file:".
After an analysis, the problem is due to the generated EXR file where the Display windows is greater than the Data window.
readEXRfile Display window : (0 - 3492)(0 - 5234)
readEXRfile Data window : (64 - 3492)(73 - 5234)
But these files are correctly opened by many applications (like Digikam, ShowPhoto or Okular).
So, by using the OpenEXR documentation, I propose a patch in attachment which solves this problem.
I have tested with some .exr files from my HD, and for the moment, I haven't found any problem but a developper should review it.