follow this instruction and fix it. God bless you
Step 1: Request unlock code
First, we need to unlock the bootloader. For Y300-0000: Visit this website (Chinese language - you might have to use Google translator) and choose Y300-0000 model.
Send an e-mail to mobile(at)huawei.com requesting a code to unlock the bootloader. (Obsolete) You can now request the unlock code directly on the Huawei website
Submit the following information via the form respectively e-mail :
- S/N number (written on the label under the battery)
- IMEI (Settings -> About phone -> Status)
- Product ID (dial *#*#1357946#*#*)
Wait 2-3 days to receive the unlock code via e-mail.