Editing completed theme .adt file⁠›››

Hello, I am slowly learning your great software. I have a .adt file that i would like try and edit but it won't open in the editor.
I have downloaded the ATVO theme and it doesn't work to good it freezes the computer.
So i tried a theme i found online that is easier and works fine but i can't change the logo or language.

I guess there is a difference between a finalized theme and the ATVO theme since that has the folders of content etc etc.

Is it possible to change logo and language with the .adt file only?

As i said, really new to this so sorry if i don't make any sense.

Forgot to say the theme i found is from 2017 so maybe that is the reason

You can try to import it in the Theme Editor via File - Import - ATVO Exported Theme. But I am afraid it will not work if the theme is that old.

What is the issue with the ATVO theme? It should not be freezing the computer... Can you elaborate? Is ATVO using too much memory, CPU, something else?

Yes i tried to impåort it but unfortunately it didn't work.
The setup is i7, 16mb, SSD, GTX1060-16mb

When I use the 2020 theme it seriously slows down the responses and from clicking show ticker it can take 20 sec until it execute. This is not the case with the old theme or the theme i have started to create myself. I have tried it also on my NB that is ASUS zenbook new model and I get the similar result.

Is there any way to get an old version of the editor that can import the theme file? It would be great if it's possible.
thanks for helping.
johan