Notifications stays empty & moderation 'Went wrong'

When i send a message from one user to another, The receiving user gets a popup and a ‘1’ shows in the ‘messages’ tab. But nothing ever goes in the notifications tab.
I tested your demo and when a message is received the message also goes into the notifications tab.

I think it’s not working for me.

also

when I click on the moderation link (when in admin), I get “Something went wrong..”
and there is nothing there!
Please advise

(great plugin though apart form some teething troubles)

https://wordpress.org/plugins/wpchats-lite-private-messaging/