Hi, after Update NC 18 to NC 20.0.4 in my error.log i found this entrys on Mass.

Icewind\SMB\Exception\NotFoundException: Invalid request for PATH-TO-FILE (NotFoundException)

But the Share seems to work...

May be this Error was also on NC 18 or NC 19, i dont know.
I made an NC Update

cd /var/www/html/ (my Nextcloud)
sudo -u www-data php occ maintenance:mode --on
sudo -u www-data php updater/updater.phar

from 18.0.12 to 19.0.6
and from 19.0.6 to 20.0.4

Debian 10 (Buster)
PHP 7.3 (php-fpm)
Apache2