Hi, @PeteSharp,
does it work with Blocs 3.5.8?
I’m still doing most of my work with Blocs 3.5.8 on an iMac with High Sierra and haven’t upgraded to Blocs 4.1 (I know, I’m a troglodyte!, but Big Sur still has too many problems…).
[EDIT] It doesn’t. Forget about it… 
Mojave is a solid OS and works well with Blocs 4 if you are hesitant to use Big Sur. It also still works with older 32-bit apps.
I had reservations about Catalina as well but it wasn’t the disaster I feared. Big Sur seems reasonable for the most part with only a few minor frustrations.
Hi @Mangla,
Yes, Easy Burger is Blocs 4 only, because it uses Font Awesome version 5. Blocs 3 used Font Awesome 4.
If you have already purchased Easy Burger, DM me your email you purchased with and I’ll refund you. 
-Pete
https://blocsbuilder.com/brics/easy-burger/
The current feedback is that Easy Burger works fine in Blocs 5