Subscribe by mail widget - where to change text "email address" and "someone@mydomain

Dear Ladies and Gentlemen
After the plugin upgrade I can't change the texts in the widget anymore. I tried the following:
1) change text in widget.php which leads to a php error
2) change text in language file: subscribe-by-email-default. When I do this nothing changes. I tried to do this in the source code or over a software (Poedit) which generates a new .po and .mo file

Could you please help me on this. The best would be precise instructions how to change the language of the plugin. I could imagine a lot of website owners ask this:slight_smile:.

Thank you very much for your help.