OPEN-0751 and SHED-14 have corrupted parts. I've checked them with quickpar, downloaded again and it's still broke. The respective parts are 09 for OPEN-0751 and 04 for SHED-14.
Did you download any/all of the other par2 files. the standard .par2 file has no recovery blocks. Did you download any of these:-
SHED-14.vol000_01.PAR2
SHED-14.vol001_02.PAR2
SHED-14.vol003_04.PAR2
SHED-14.vol007_08.PAR2
quickpar will tell you how many blocks you are missing, and then, with whichever you need from the above, you should be able to recover. If you have all 4 of the above, and you are still unable to recover, then I will need to reup, but please confirm you've got all 4 of the above downloaded too.