Could not create directory "mwstore://local-backend/local-public/4/44". see https://www.mediawiki.org/wiki/Topic:Shsy2ih2cft90uc8
Yes, I know
I've tried several times to fix this. I took my backup to the ABUG meeting in case somebody knew enough to fix it, but didn't get a chance - other things got done.
I'll check the link to see if there's anything different from last time I tried.