That link leads to a thread about an error 23, not a -23, so keep in mind most stuff there regards a 23.
So is it an error 23 or an error -23?
They are very different. If its a -23 as it says above, then there may be something wrong with your disk. Run Disk First Aid and see what it says.
If its a 23, then as in the linked thread, I have no idea...
FYI: -23 = openErr - requested read/write permission doesn't match.