Plugin disabled but some strings translated in WP-admin

That depends on your default qTranslate language. The plugin *always* attempts to load the admin area in the default language, so if there are any strings that can be translated in that language, they will be.

To change that, you may filter ‘wc_qtml_admin_default_language’ in your theme to return false (default is true).

I have not installed qTranslate but mqTranslate.
The default language set in mqtranslate settings is English.
Before to activate your plugin that issue was not shown.

So I suppose that your plugin when activated force something that when disabled is not restored automatically.

What do you suggest. I need that when I delete your plugin all strings in my admin works without any issue.

Thanks
s.