1. After update from "14.3.B.0.288" to "14.3.B.0.310"
2. reboot now
3. flash only "14.3.B.0.288"'s kernel by using Flashtool
4. get root using EasyRootTool_v8
5. do it -> Z1C-lockeddualrecovery2.7.xxx-BETA.installer
6. reboot now
7. flash only "14.3.B.0.310"'s kernel by using Flashtool
8. that's all
2. reboot now
3. flash only "14.3.B.0.288"'s kernel by using Flashtool
4. get root using EasyRootTool_v8
5. do it -> Z1C-lockeddualrecovery2.7.xxx-BETA.installer
6. reboot now
7. flash only "14.3.B.0.310"'s kernel by using Flashtool
8. that's all