I know it’s solved. But I got the error message, too - since 2 hours ! suddenly.
And I don’t know, I never configured memcache. The official Docu has something to tell about this:
A memcache is not required and you may safely ignore the warning if you prefer.
Why you guys bind the error message to something, which is actually not necessary due to the nextcloud programmers ? Can it be, that configuring the memcache removes the symptom and not the cause !?
Why does this error message appear in the 1st place if having a memcache is not required !! ?!!!