The install script is trying testing a post through cURL to the https://www.webassist.com server.
The error on the diagnostic page is saying that the cURL post failed.
if the cURL post failed, it will be a problem on the server side preventing the connection to our site.
attached is a cURL test file you can use, if this cant connect to the https://www.webassist.com server, you will need to contact the host to determine why.