Coursepress Pro Translation does not work

Hello :slight_smile:

I am trying to translate the Coursepress Pro plugin using the Coursepress theme that came with it.

I have downloaded the PO file from wp-content/plugins/coursepress/languages, I have renamed it into cp-el.mo, I have translated a few terms and I re uploaded both the .mo and .po files.

I have also tried to set the define ('WPLANG', 'el'); in wp-config, but the translation does not work.

I have also verified the files with PoEdit but still the same. I finally tried the locale el_GR but no luck.

This did not help either: https://premium.wpmudev.org/forums/topic/translation-to-russian-poedit

Any Ideas?
I am using Wordpress 4

Kind Regards
Stratos