Caused by a system code error. The new language listening book is a software with some out-of-order programs, and the binding program in it can't bind the library account because of the wrong code order. The solution steps are as follows:

1. We send this package to the computer, and then use the computer to change the file suffix to vng format.

2. Then open this software and you can see a bunch of codes, then find the binding program and change the order of the codes to save.

3. Finally, the problem of account binding failure can be recovered after being sent to your mobile phone for reinstallation.