HELP!!

[Chuckvid]

I can't open a couple dmg files, when I try to open them I get the message "The following images couldn't be opened - image java.update,dmg". "Reason - Image not recognized". Is there something that my system is missing? If so, what do I have to do to get it in my system?
Mac Mini Late 2009,
Processor 2.26 GHz Intel Core 2 Duo,
Memory 4 GB 1067 MHz DDR3,
Startup disk Macintosh HDD,
Graphics NVIDIA, GeForce 9400 256 MB
S/N YM0166KY9G5

I surely can use the help.

Chuck

 

[Cory Cooper]

-What version of Mac OS X?
-Can you open any DMGs?
-Where did you get that Java DMG from?

C

 

[Chuckvid]

1. OS 10.11. El Capitan just upgraded from OS 10.9.5 Mavericks this past Saturday Oct.10
2. Yes, I can open most of them.
3. down-get.com, softonic