impossible to subscribe, widget dont working

Hi,
can you help me please, the plugin widget dont working – it is impossible to subscribe for the newsletter. The problem appears with the new template of my site.

When I press subscribe button, appears the inscription: Oops.. Unexpected error occurred.

Another problem – the letters on the name and email fields of the widget are white and the writing is problematic.

Creating and sending newslettes is perfectly as on the old temlate.

My site ishttp://www.mamairvaikas.lt/
Widget is on the right of the footer.

Thank you very much

https://wordpress.org/plugins/email-subscribers/