Understandable question (I’ve done this myself) but unfortunately when you are logged out and try to do something in an ‘old’ open window the connection to the code is broken. So the server can now do nothing but crash with a fatal error. You have two windows trying to operate on the same code, but in two completely separate worlds (‘sessions’). There is no way round that.
To put it another way, when you try to run any “edit’ but don’t have access to those parts of the code, we can’t fail gracefully. The server no longer has any idea what this (now) unknown intruder is trying to do.
It’s simply a case (and no personal criticism intended) if we do something silly we get a silly response 🙁
Also, this being an open site, I should be able to view with or without log in, just not edit.
I agree, but you didn’t ask the server to let you view the individual, you asked to be able to edit it. That’s a totally different URL, (…something/editinterface.php……. rather than …/individual.php), and the server isn’t allowed to go there if you’re not logged in. It would in effect seem to the server like an attempted hack, something far more seriously bad than simply attempting to view a private individual.