SNWeb can fail to load for a few different reasons.
School Network Firewall
If you are trying to launch SNWeb using internet on a school campus then specific URLs must be whitelisted by the school IT department.
The relevant URLs are listed here:
Comcast Xfinity ISP
If you are trying to launch SNWeb using internet provided by Comcast Xfinity then you need to disable the protected browsing security feature.
The process for disabling Comcast Xfinity protected browsing is outlined here:
Cox Cable ISP
If you are trying to launch SNWeb using internet provided by Cox Cable then you need to disable the advanced security features.
The process for disabling Cox Cable advanced security is outlined here:
Malwarebytes Browser Extension
The Malwarebytes browser extension has also been reported to interfere with SNWeb loading.
If further assistance is required please submit a ticket.