Q: recovered deleted dmg file but now it can't be mount

hi,

I recovered dmg files that i deleted from a external drive with disk drill.

they were all encrypted. but i have the password.

disk drill  recovered all of them. (the dmgs show their correct size as before i deleted them)

out of the 16 dmg files i recovered,  i can only open one.( the others are unable to mount).

I never overwrite anything on the external drive after i deleted the files by mistake.

any thoughts?