Since the cache is apparently broken I had to disable it here on elk.net.
Apparently file-based took the opportunity to do some work, I'm not sure why since it should not be a default fallback, but it does and that's it.
A bug? Likely.
Yet another reason to remove file based O:-)
Poor file based... :( :P
I feel something is pretty broken with the new way topics are marked as read... :-\
Fixed most of them, two were the problems:
1) class names collision (Memcached and ElkArte\sources\subs\CacheMethod\Memcached), fixed by adding \ to the PHP Memcached,
2) is_miss was set to true only if $result was null, but some accelerators return false.