I was using LR3 and Win 7 without any issue, but ever since I have gone to LR 4(.2) and Win 8 and I try to export a TIF/NEF file to a compressed (1-2000mb) JPEG, about 50% of my files don't render properly, and I get a "FILE CANNOT BE WRITTEN" error.
Strangely enough I can select the "Export to Email" size or export as full-size JPEG and it works fine, but no sizes in-between.
Can ANYONE help?