I'm experiencing a strange problem that cropped up yesterday morning.  I am suddenly getting a 'page not found' error when trying to access my community in my sandbox org.  I have not changed any of the custom URL settings in weeks and was accessing and using the sandbox community the very night before without issue.

Sandbox: https://sandbox-hirebotics.cs51.force.com/ (<-- page not found error)

Production:  https://robots.hirebotics.com (<-- works fine)

After three phone calls / go-to-meetings with salesforce support they can't figure out what's going on.  Their latest guess is that my product custom URL in sandbox (which is copied into sandbox upon a refresh, which I haven't done in a week) is set to "in development".  But they can't tell me why that's a problem now nor how to change that, assuming that's the problem.  They suggested I post here.  See below.


Now, I also tried spinning out another developers sandbox from my working production org and I'm seeing the exact same problem accessing the login page hosted from this new dev org.

Note that the error page below is being served from my org as the email us link connects to my email address.


Also, both my sandbox and dev sandbox are hosted on CS51, if that's relevant.

Any idea what's going on?