wp_cache_get last_changed microtime error
in WORDPRESS 4.7 IN /wp-includes/functions.php line 7451
microtime error: if you are using MEMCACHED.
the $last_changed if it was not set, it gets set to what ever
the microtime() is at that moment.
previous versions of this file it was time(),
unless you call microtime with the bool of true,
you will get a space in between the "msec sec".
now this is fine and dandy, but if you are running memcached
as your caching device, the space in the cache key causes all sort
of weird things to happen.
//solution add true inside microtime
$last_changed = microtime(true);