Emergency help, note4 upgraded MIUI8 stable version and could not receive verification code.

It may be due to the following circumstances:

1. The SMS storage of the mobile phone is full. The short message storage capacity of mobile phone is limited. If you don't clear the received short message in time, you won't receive the subsequent short message. It is recommended to delete the short message and try again.

2. Your mobile phone has not been turned on for a long time or is in a bad signal place for a long time, which will make the short message sent to you invalid because it is expired. Suggest to try another place; (the validity time of the verification string is: 2 minutes)

3. It is related to the local gateway. Due to the large number of local short messages in some time periods, the short message center is busy, and the short messages may be affected, delayed or lost. I suggest you try again later in another time period.

4. It is related to the short message platform of the operator. There are individual failures (inconsistent orders)