Not working with any Theme – what to do?

Hi, i am using WP 4.3.1 and the readme theme. I installed your plugin because the theme devs suggested to do so. They made the pot file compatible to this plgin, they say.

http://themeforest.net/item/readme-a-readable-wordpress-theme/9167043?s_phrase=&s_rank=5

But i have the problem that no matter what theme or plugin i take your plugin is not working.

I have no clue how to trubbleshoot this.

I took your beginners guide and went through it step by step. All right set, everything in place as it should be. But what i get is just 5 Words to translate which is:

Readme, URL to the theme dev site, and things like that. But nothing concerning the actual words i want to translate.

What shall i do?

Thanks for any help!

https://wordpress.org/plugins/loco-translate/