Gateway Page isn't redirecting properly

Hi There,

We have a gateway setup on a VM that has been running for a couple months no problem. I have been able to access the Gateway both from the VM itself and remotely. However, I am no longer able to connect to the gateway due to this error:

I can still connect to the project through the designer and make/save changes, but I cannot access the gateway at all. I have restarted the VM multiple times and cleared all cookies/data in multiple browsers (Firefox and Edge). What else can I do here?

Thanks!

Edit: Also gives the same error in Chrome.