Sizergh Castle and Garden is a stately home and garden at Helsington in the English county of Cumbria, about 4 miles (6.4 km) south of Kendal. Located in historic Westmorland the castle, a grade I listed building, is in the care of the National Trust along with its garden and estate. It is the home of the Hornyold-Strickland family.
In 2016 the Sizergh estate was included in the newly extended Lake District National Park. Wikipedia.
The great Barn at Sizergh Castle, processed in PL7 v7.7.2 (Windows):
I am only surprised that the photo is displayed correctly on @mrcrustacean screen in DxO. If it were due to the calibration, the image in DxO would also be dark. I therefore assume that it is due to the export. I’ll do a few tests tomorrow. Nevertheless, a calibrate screen is a recommendation.