Yeah 100% sure the Heli update caused this problem.
I switched to the Legacy Build and it's working again.

So CfgAddons/PreloadAddons needs to be fixed.

http://feedback.arma3.com/view.php?id=18341

http://forums.bistudio.com/showthread.php?185098-Custom-function-quot-CurrentGrenade-quot

Thanks for your try. :)

And how i can see which grenade is at the moment active?

this:
"2: Magazine state (true - loaded, false - not loaded)"

can't be used for that because every throw object has "true".
Or did i understand anything wrong?