It's a harmless notification and it is related to PHP version, you should only see the message if you've got error reporting on so it shouldn't show on a live site. If it bothers you you can do what it says and put the $ inside the brackets, it gives you the file location, name and line numbers to change. (there was only two for me).
Hi Gnarly
Yes Thank you.
I know, this is why I'm Testing and report back to the Forum and Developers.
Anyway, I trying to rebuild the Error with switching PHP back and forth, error not more appear. So I'm happy with this :lol:
Best Regards, Marcel