I have that problem too now, only just upgraded from 138a to 139h.

Got the charset error message during upgrade:-
---------
1253 COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'latin1'
in:
[CREATE TABLE counter_history_clean as SELECT * FROM counter_history WHERE 1 GROUP BY startdate COLLATE utf8_general_ci;]
---------
Although I had set the installer_params.php to accept 'utf8' and "ignore_db_charset" to "TRUE" in the hope these would by-pass the error messages or force the issue.

My database host is set for utf8 on all tables.

Now entering the Admin section and receiving the message to patch the databases to a higher level.

I've already gone through the "3 Easy Steps" - creating a new DB, exporting the contents of the old DB, importing the contents into the new DB moving the entire site folder to a new location, as a test run, altering all configure files and others to reflect the new location, the new db, etc., etc. So my end appears to be fully-functing, but the interaction with the db isn't working and needs a corrective fix.

What and where it is?

I've followed a few threads over the last 18 hours and found no clear, effective answer to the question of correcting the CHARSET and DB issue.

Current database patch level on the cart's admin section reads 1.3.8

I've also tried running zc_install a couple of times to upgrade the database, and back to the [1253 COLLATION 'utf8_general_ci'...] ERROR message.

If the cart is defaulting to 'latin1' and still offers the option to override to 'utf8' then how do we resolve this conflict?

1. Alter source code?
2. Change all the database, creating new ones in 'latin1' format?
The current DB settings include:-
1 . MySQL charset: UTF-8 Unicode (utf8)
2 . MySQL connection collation: utf8_unicode_ci

From an amateur's point of view this is not something I want to be meddling with unless there is no alternative and there are clear instructions, guidelines and safety hats provided.