1. I have used the loco translate and also PO edit, but perhaps these words are hard coded?

I will give you some examples:

a.
Read by tester10 @ 2 April 2020 11:56
So in this case I can’t find “Read by” using POEdit. I would like to translate “Read by”

b.
Message box size:23 of Ongelimiteerd

In this case I can’t find the string: “Message box” which I would like to translate.
Also “of” is English and I would like to translate this

Thanks
Nadia