After tons of web trolling I found a work-around to the OS X 10.11.4 driver loading problem.
The short answer is you need to disable system protection which blocks unsigned drivers. The following link describes how to make the change. Sorry I closed the link which pointed me to this solution and I can't find it. But the following directions work.
http://www.macworld.com/article/2986118/security/how-to-modify-system-integrity-protection-in-el-capitan.html
Quick list of steps
1. Open the "Terminal Application" - then type > csrutil status
> csrutil status
System Integrity Protection status: enabled.
Now Disable Protection
2. Shutdown/turn off your system
3. Restart your system - while holding down the CMD+R (Command and R keys). Release once the system starts loading.
This will boot your system into recovery.
4. Open terminal from the menu - ignore the recovery options in the foreground.
5. From the terminal window type
> csrutil status
> csrutil disable
6. Reboot the system and reinstall the Line6 drivers from LIne6 Monkey.
To restore the system back to its original state follow step 5 again from recovery and type 'enable'.
> csrutil enable