Asian server has moved from Singapore to Hong Kong.
The current version of region changer only includes Singapore(closed) and Australia.
I edited the script_config.xml and replaced the Singapore part with this, and it's working well. Idk if it helps
<host>
<name>Hong Kong</name>
<short_name>HK</short_name>
<url>wotasia2.login.wargaming.net:20016</url>
<url_token>wotasia2-2.login.wargaming.net:20016</url_token>
<public_key_path>loginapp_wot.pubkey</public_key_path>
<periphery_id> 502 </periphery_id>
</host>