This occurred today and I checked all of our perspective dashboards on this gateway and they all seem to be working just fine. Nobody can get the main page to load. A restart might solve this but I'd like to see if anyone has experience with this so I don't have to restart.
Any errors in the gateway logs?
Hi! We’ve just ran into this issue ourselves. DevTools say no errors. In fact, we receive no HTML at all…

The other functions (drivers, database, etc) are all clear. Just the gateway home service appears to be down. Multiple browsers were tested, machines, direct access to the IP:8088 internally resulted in the same output.
We are running 8.1.50, just updated, but it has happened to us in the past as well. We were only able to solve it by restarting the gateway. I’ll try to extract the logs to analyze if there is any outliers that could help us identify the issue.
A complete lack of response (that your browser is apparently not detecting as an error) strongly indicates some interfering middleman between you and the gateway. It's not impossible that it's some underlying issue with Ignition, but I'd consider it much less likely than something about your environment.
Yeah, that was the first thing that came to my mind. That said, I connected directly to the server (without any middlemen interference), and still got that empty page. Mind you, Perspective was working fine all the way, and it is accessed through the same endpoint (except the path).
Sadly, we had other issues related to an issue we are dealing with the IA’s Support team, and this issue forced us to reboot, so we are no longer having this issue at this moment.

