Can't update from 10.0.0.2.1 to 10.0.0.3

are the files in the list the same?

Yes, the exact same files

dmitry I really appreciate all the time and effort you put to help me. Thank you.
I must leave for now and won't be able to reply for a couple of hours.

no worries, tomorrow I will try to assist you with fixing the remaining issues

I have other problems. I can't "reshare" files apparently even though the "Allow resharing" setting is checked and "Allow users to share via link" is also checked.

I don't trust this installation. I will re-install from scratch. (Ubuntu and Owncloud)

Okay, tell me if it solved your problem

Re-installing it made me realize I may know what caused the problem in the first place.

At some point in the Ubuntu instructions it says to "Set Strong Directory Permissions" and sends you to that page:
https://doc.owncloud.org/server/latest/admin_manual/installation/installation_wizard.html#post-installation-steps-label

The thing is that all this is hard for me to understand but it recommends to use a script which I did.
Could it be that script that screwed my onwcloud installation?

Now I did not modify anything in the script since I installed owncloud in /var/www/owncloud

I am ready to do it again, on my new install, but before I do can someone confirm that this is the proper thing to do please.

So what I am about to do is:
1. create a file named script.sh
2. nano script.sh
3. paste script:
#!/bin/bash
ocpath='/var/www/owncloud'
ocdata='/var/www/owncloud/data'
htuser='www-data'
htgroup='www-data'
rootuser='root'

printf "Creating possible missing Directories\n"
mkdir -p $ocdata
mkdir -p $ocpath/assets
mkdir -p $ocpath/updater

printf "chmod Files and Directories\n"
find ${ocpath}/ -type f -print0 | xargs -0 chmod 0640
find ${ocpath}/ -type d -print0 | xargs -0 chmod 0750
find ${ocdata}/ -type f -print0 | xargs -0 chmod 0640
find ${ocdata}/ -type d -print0 | xargs -0 chmod 0750

printf "chown Directories\n"
chown -R ${rootuser}:${htgroup} ${ocpath}/
chown -R ${htuser}:${htgroup} ${ocpath}/apps/
chown -R ${htuser}:${htgroup} ${ocpath}/assets/
chown -R ${htuser}:${htgroup} ${ocpath}/config/
chown -R ${htuser}:${htgroup} ${ocdata}/
chown -R ${htuser}:${htgroup} ${ocpath}/themes/
chown -R ${htuser}:${htgroup} ${ocpath}/updater/

chmod +x ${ocpath}/occ

printf "chmod/chown .htaccess\n"
if [ -f ${ocpath}/.htaccess ]
then
chmod 0644 ${ocpath}/.htaccess
chown ${rootuser}:${htgroup} ${ocpath}/.htaccess
fi
if [ -f ${ocdata}/.htaccess ]
then
chmod 0644 ${ocdata}/.htaccess
chown ${rootuser}:${htgroup} ${ocdata}/.htaccess
fi
4. chmod +x script.sh
5. ./script.sh