Avada Website crashes after fusion-builder installation

I have installed the paid-for AVADA, got and installed the token, installed the fusion-core and all was good. Next I tried several times to install the fusion-builder, and every time the site crashes in a 500 Internal Server Error.
I’ve paid for support … how do I get to it?

Hello!

If you have problems with your purchased item, I strongly recommend you to contact the author for bugfix support. In this case to reach the author of Avada theme please access this url:

Have an wonderful day!

Thanks! How do I delete this resolved post?