@eta, for clarification: it's not even trying to open the CHD, it just doesn't find it because it's not searching in the right place(s)!

As I said above, when I put the software-list CHD (i.e. mac750.chd) in one of the ROM paths it will be found and verified successfully!! So it's not that software-list CHDs can't be verified at all.

A mind is like a parachute. It doesn't work unless it's open. [Frank Zappa]