Hi everyone,
I’m trying to update my Nextcloud instance on a Raspberry Pi but I got this:
There are some warnings regarding your setup.
MySQL is used as database but does not support 4-byte characters. To be able to handle 4-byte characters (like emojis) without issues in filenames or comments for example it is recommended to enable the 4-byte support in MySQL. For further details read the documentation page about this.
Your web server is not properly set up to resolve “/.well-known/caldav”. Further information can be found in the documentation.
Your web server is not properly set up to resolve “/.well-known/carddav”. Further information can be found in the documentation.
No memory cache has been configured. To enhance performance, please configure a memcache, if available. Further information can be found in the documentation.
You are currently running PHP 7.0.33-0+deb9u7. Upgrade your PHP version to take advantage of performance and security updates provided by the PHP Group as soon as your distribution supports it.
The PHP OPcache is not properly configured. For better performance it is recommended to use the following settings in the php.ini:
opcache.enable=1
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=10000
opcache.memory_consumption=128
opcache.save_comments=1
opcache.revalidate_freq=1
The database is missing some indexes. Due to the fact that adding indexes on big tables could take some time they were not added automatically. By running “occ db:add-missing-indices” those missing indexes could be added manually while the instance keeps running. Once the indexes are added queries to those tables are usually much faster.
Missing index “owner_index” in table “oc_share”.
Missing index “initiator_index” in table “oc_share”.
Some columns in the database are missing a conversion to big int. Due to the fact that changing column types on big tables could take some time they were not changed automatically. By running ‘occ db:convert-filecache-bigint’ those pending changes could be applied manually. This operation needs to be made while the instance is offline. For further details read the documentation page about this.
filecache.mtime
filecache.storage_mtime
mounts.storage_id
mounts.root_id
mounts.mount_id
Please double check the installation guides 
, and check for any errors or warnings in the log.
Check the security of your Nextcloud over our security scan .
When I check the update available, I got this:
Version
Nextcloud 15.0.14
A new version is available: Nextcloud 16.0.7
All apps have an update for this version available
Apps with available updates
Update channel: Stable
Why I can’t get to the last version 18?