I am sorry to report that access to the wiki seems to stop at various points, then if you wait an hour or two or maybe 3, it comes back.
I notice that it does this when I am editing the wiki, after a number of saves, the text screen
will go blank and if I am in the Dev Manual, the Opencpn
Manual can be viewed normally, but if I go to edit it goes blank too.
If I just stop and wait for 3 hours it is usually back as normal and can be edited a limited number of times before it will do that again.
It is troublesome when you are in the middle of doing something.
I have tried clearing the cache and rebuilding the index. I will inquire at the dokuwiki forum about this behavior.