Right now I am on Yosemite.
I did fresh download Firefox (from Safari browser) and XN (inside add-on) then install.
I export my data from other Mac, and import into this.
LOOKS GOOD!
Thank you Tobwithu.
FYI:
Safari, it seem not work properly,
I did send log file to Tobwithu for review.
I know it is "beta", but it is nice to have "works!".
Yosemite Beta with Safari
It seem work well...
Except one...
When X-notifier checking...
The XN Logo blink that cause whole XN host listing bounce up & down about 2mm.
I did create screen video and send to Tobwithu for his review...
I hope he able to fix it, before Yosemite release sometime in couple of months.
Thanks, CFBancroft