How to fix can't Update OTA after using RootZenfoneKitkat, here to provide a solution.
Update-Recovery.bat:
Download: http://adf.ly/tf5Vp
Mirror: http://adf.ly/tf5FH
Recovery:
ZenFone 5
Download: http://adf.ly/tf5Pz
Mirror: http://goo.gl/5MUwZb
ZenFone 6
Download: http://adf.ly/tf5YN
Mirror: http://goo.gl/uOwKgY
Download the Update-Recovery.bat and the corresponding <version>_<region>_recovery.img file, put Update-Reocvery.bat' inside the RootZenFoneKitKat folder and replace therecovery.img` in files folder with the one you've downloaded.
Execute Update-Recovery.bat to flash stock recovery for your ZenFone and apply OTA update again, should fix the OTA problem.
Source: http://23pin.logdown.com/posts/240246-zenfone-if-you-failed-to-apply-ota-update-after-using-rootzenfonekitkat
