Why cant I open Zip Archive made with Mac?

Question

I made several Zip archives of some of my photographic files, but when I try to open them I get message that I do not have permission or an error occurred. I have tried Apple's Archive Utility, Stuffit Expander and recently The Archiver with no success. Can anyone help me unarchive these as I have lost the originals on an external drive that became corrupted. I only archived the files in case of this happening, but now rely on opening these or loosing hundreds of photographs. There is data there, because only after unzipping the files, which takes a long time, do I get the 'permissions' message with Apple Archive Utility. If I used MediaRecover, or similar, can I get at the files this way? Thanks in anticipation of an answer to a frustrating situation. I have read through the discussions on this topic but can't find an answer? Chris

Answer 1

Mac OS X (and any Unix system) makes use of Disk and file permissions,
if you don't have sufficient rights on one of these, the you won't have permission to open it.
since it works as:
file permissions+disk permissions=actual permission
for example:
no access+read/write=no access
select the archive and press cmd+i (or from the menu use file->get info)
and take a look under "sharing and permissions"
you see a list ordered like this:
<user name> <permissions>
if you want to extract a archive changes are you need permissions to modify it
so make sure the permissions are like this:
<your user name> read and write
if you can extract them, make sure the permissions for the files are at least "read" for your account then you should be able to open them (but you probably want "read and write")