Not working on some sites and works well on another…

You don’t need a translation file for the english language – it’s hard-coded into the source code of WordPress.

I’d love to help you if you can follow the instructions in the other thread you posted:
https://www.ads-software.com/support/topic/installed-on-wp-v45-ja-but-not-working?replies=3

I’ll leave this topic open until we can find a solution.

Thanks!

no, added admin english files, and nothing changed ??

Looks like this stupid plugin makes errors and stops your great plugin functionality ??

Configure SMTP https://www.ads-software.com/support/plugin/configure-smtp

Maybe together with php5.3 – installed on another server, and the cause was only this smtp plugin. but on another server with php5.3 it didn’t worked even when i disabled all plugins.