We all know that feeling, we are reading somebodies wiki pages and we click and get...
Page not found
But, is this an indication of intent, a page that can't be reached from here, a link to a deleted page, or a link to a wiki that no longer exists?
How to move forward?
If this is on your own wiki, logging in should be your first step. It might not be the whole answer, as the client will likely have remembered that the remote wiki was unreachable. So, you will need to click on the tilted flags in the navigation bar to refresh the client's memory on how to reach those remote wiki.
The client knows the context in which the wiki was looking for the page, so could provide some extra help.
Maybe one, or more, of those remote wiki is not reachable, either because that wiki's server is off line, or if we are reading in a secure context and the remote wiki is not available over https.
Navigation Bar with unreachable wiki.
If none of the flags in the navigation bar are tilted, it is probable that you have found a link to an as yet unwritten page, or a page that has been deleted.
If a flag is tilted over, the client has remembered that the remote wiki was unreachable when it tried to reach that wiki. Clicking on the tilted flag tells the client to retry the connection to the remote wiki. The flag will spin while this happens, and it will stop tilted if the remote wiki is still unreachable, or untilted and replace the greyscale gradient with the remote wiki's flag if it is now reachable.
If one, or more, of the navigation bar flags that were tilted are now untilted clicking on the link again will retry to locate the page. If none of the flags are still tilted, and the page still not found it is likely you have found a link to an as yet unwritten page, or one that has been deleted.
If you have got here, and some of the flags are still tilted. Are you reading from a secure context (https)? This might just be an indication that the remote wiki is not available using https. We can try the possible page locations to see if those remote wiki are available, and if any of them have the page we are looking for. If that finds the page, and want to read it within the lineup, it might be possible to load the lineup using http.