Backing up Blackberry 9810 & 9800 desktop software on a Mac with OS X El Capitan 10.11.3. Does not work. How can i get this sorted out??

I have down loaded the blackberry desktop software for mac at least 4 times and can not get it to work.

Need to back up the 9810 and load it to a 9800.

Please assist.

I see from other coms that this is previous problem. I have checked with Apple Support and they say there are no restrictions on their side for this. It must be with Blackberry??

Please assist urgently.

Thank you