Default [Q] TWRP: ADB sideload option missing - help

Guys, I need your help today. Earlier on I was gonna sideload a file to my device, when I realised that 'ADB Sideload' option in my TWRP is missing. Gone, just not there anymore. I haven't used it for some months, I updated to latest version 2.6.3.1 a few weeks ago and today I discovered that - bugger.
I searched the net, but apparently I am the only one experiencing that. There is advanced option > Fix permission, file explorer, everything else but the option 'ADB sideload'.

If you have any idea how to fix that I'd be happy. For your information: i9300 with SlimBean 4.3.1 and Yank-Kernel 1.6g; TWRP 2.3.6.1

Thanks.