Admin Console non-responsive

[-dp-]

I'm running FMS 16 on macOS 10.12.6. FMS is up and running, and I can access the hosted databases. But I can't get into the admin console. When I enter the credentials, it just sits there. It doesn't throw an error. It just doesn't react at all. Same thing when I intentionally enter an incorrect passcode. No error. Same behavior whether I use Firefox or Safari. Same behavior whether I try to come in remotely, or if I work directly from the server as localhost. So, something is wrong with web services rather than FMS, right?

[-dp-]

I finally contacted FileMaker support about this. It turns out that I had the wrong version of Java. I had set the Java preference pane on the server to check automatically for updates, and was consequently suckered in when it popped a warning about an urgent security update. I was up to Java 151. I had to remove Java and run the latest FMS update, which installed Java 144, and restored access to my console.