Try File Manager/whichever folder you have for AbanteCart 1.2/Download is 3rd top folder, change permissions for that to 0777 & most likely change any subfolders & files permissions too - there's only a few of them. I don't have downloads on my site so I'm only guessing with my advice. Would be wise to make a not of the original permissions so you can change them back if I'm wrong. Just a self taught wishes-she-was-better-at-it-all-cos-it-is-scary-stuff what my foster son calls tech-head. Fingers crossed for you.