Version Mysql: 5.5.5-10.3.22-MariaDB-0+deb10u1

We had not encountered that yet. We'll check.

:-( Thanks fplanque. final user suck :-/

@fplanque wrote earlier:

We had not encountered that yet. We'll check.

It looks like I managed to solve it! I don't know exactly what worked because I made the following attempts:
1) Restore the last database backup (02/2020), but there was an error.
2) Back to the old version: It didn't work!
3) Restore an older back. It worked but I lost 10 years of publications :-(
4) I came back to version 7.1.2 and, for some unknown reason, the upgrade script worked!

Mental Note: Only update when the developers publish the auto-upgrade script! And always make backups first!

PS: All comments have been lost :-(
PS: Excuse me my poor english :-(

Do you still have an old copy of the database for the previous version?

If you the current database under a new name you could compare the sizes of the old and new to get an idea of what you have lost.

If you can remember a part of text specific to a comment you can search the saved database to see if it is there. The commenst may exist but are not being processed properly.

You could also try a new install of 6.11.5 and import the old database.

@amoun wrote earlier:

Do you still have an old copy of the database for the previous version?

If you the current database under a new name you could compare the sizes of the old and new to get an idea of what you have lost.

If you can remember a part of text specific to a comment you can search the saved database to see if it is there. The commenst may exist but are not being processed properly.

You could also try a new install of 6.11.5 and import the old database.

Yes I have a file sql.db (backup of 22/02/2020). When I try dump this backup in new db to install 6.11.5 an error has occurred.

I will try this approach. Thanks!

@amoun wrote earlier:

Do you still have an old copy of the database for the previous version?

You could also try a new install of 6.11.5 and import the old database.

It's work! I could to restore version 6.11.5, with all the comments! Thanks so much for your good advices!

Let's hope all problems can be as much fun :)

I keep blowing up B2 on my test server when upgrading. I got a clean upgrade by going to features, system, maintenance and clicking
CHECK database tables
OPTIMIZE database tables
ANALYZE database tables
Check/Convert/Normalize the charsets/collations used by the DB (UTF-8 / ASCII)
Worked for me

I cannot reproduce this on upgrade from 6.1.15 to 7.1.3:

It looks like the message "Row size too large. The maximum row size for the used table type, not counting BLOBs,
is 8126. This includes storage overhead, check the manual. You have to change some
columns to TEXT or BLOBs(Errno1118)" depends on some mysql setting. I didn't investigate this deeply but these discussions may help:

https://dba.stackexchange.com/questions/90096/row-size-too-large-8126
https://dba.stackexchange.com/questions/6598/innodb-create-table-error-row-size-too-large

I had this problem and what saved the day for me is one line added to /etc/mysql/my.cnf:

innodb_strict_mode = 0

Hope this helps other people as well.