Download latest Android KitKat 4.4.2 110k4 SD card firmware for MK808B Plus TV Stick from here or from here. To flash firmware on this box via SD card read this article.
Download latest Android KitKat 4.4.2 110k4 PC flash firmware for MK808B Plus TV Stick from here or from here. To flash firmware on this box via AMLogic USB Burning Tool read this article.
Download previous firmware from here.
Archive name: MK808B Plus_110k4_Flashtool / MK808B_PLUS_110K4_SDCARD 4.4.2 fw
Image: MK808B Plus_110k4_Flashtool.img / MK808B_PLUS_110K4_SDCARD.zip
Archive file size: 414 MB / 439 MB
Platform: AMLogic S805
Build number: m201-user 4.4.2 KOT49H 20150330 test-keys
Caution Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.