Download Android KitKat 4.4.2 stock firmware for Zidoo X1 TV Box from here or here. Download previous firmware from here. 
Firmware details
Archives: Zidoo X1 v1.0.16 fw
Archive size: 325 MB
Image: zidoo_x1_v1.0.16-ota-20150729.zip
Platform: Allwinner H3
Build number: dolphin_fvd_p1-eng 4.4.2 KOT49H 20150729 test-keys
Changelog  System
1.Fixed the style of navigation bar, changed into hiding the navigation bar manually.
2.Fixed the problem of cover input box when opening the input method.
3.Fixed some apps have no navigation bar.
4.Fixed some apps can't fullscreen.
5.Fixed notification icons are far too large.
6.Added the switch of keypad tone.
7.Fixed problem that VPN can't connect.
8.Fixed some sdcard can't update fireware.
Video Player
1.Fixed the 24Hz switch default close in interal player.
2.Saved audio track setting.
3.Saved subtitle setting.
4.Repaired the problem of when there is bilingual subtitles, subtitle display in the upper left corner.
5.Added test tips when closing subtitles.
6.Set English as the default language.
File manager
1.Repaired problem that it can't cut between the recovery storage devices
2.Fixed the error problems of translation
3.Solved the click failure problem of screening bar
Setting
1.Fixed setting has Bluetooth button when plug in a USB Bluetooth dongle.
KODI
1.Fixed the debug display error with dropped frames.
UI
1.Fixed the application name as ZIUI Simple
2.Fixed the problem of Vietnamese words lost
3.Repaired the error problem of translation
ZIDOO RC
1.To connect devices automatically when entering apps
2.Repaired some insensitive bottons
3.Repaired the problem that when it's mouse code, the mouse can't move to the bottom
USB installation
1.Fixed English as the default language
Easy cast
1.Repaired the app error problem when changing the device name.
 
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.