Why does Net Extender not work on my MAC?
Net Extender is deprecated for MAC OS 10.9 (Mavericks) and 10.10 (Yosemite). Support is limited to critical bugs and security vulnerabilities only. Support suggests using SonicWall Mobile Connect instead. Mobile Connect works with any SRA, SMA or UTM product that SonicWall offers.
Below is the link to the download:
SonicWall Mobile Connect download.
For mass deployment scenarios see Apple's Device Enrollment Program.