The problem that the Battle.net client cannot log in is because the installed Battle.net client login is not caused by the latest version, and the version needs to be updated.

1. First, open Blizzard Battle. Net, click the Blizzard icon in the upper left corner, and click to expand the settings.

2. Enter the settings and click the inside at the bottom left.

3. Click to switch to the beta version.

4. Prompt that the beta version will be downloaded and Battle.net will be restarted. Click Yes.

5. After the download is completed, it will be installed automatically.

6. After the download is completed, you will be prompted that the update has been selected. To restart Battle.net, click Restart Now to finish.

7. Then you can log in normally.