Can't access to Arcade

Today, one user indicate to me that are a problem,
In some posts of some threads, at the top of site appears this error:

PHP Warning: Illegal string offset 'type' in ..../includes/class_postbit.php(345) : eval()'d code on line 57

Only in some pages of some threads.

But now, I can't access to arcade, if click to access appears this error:

PHP Warning: mysqli_query(): (42000/1055): Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'mydatabase.c.champ_gid' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by in ..../arcade/functions/dbclass_mysqli.php on line 193

PHP Warning: mysqli_error() expects exactly 1 parameter, 0 given in ..../arcade/functions/dbclass_mysqli.php on line 512

There is a SQL error.
You can contact the board administrator by clicking here

Error Returned
mySQL query error: SELECT c.champ_gid AS GID, c.champ_mid AS MID, c.champ_name AS name, COUNT(c.champ_mid) AS total, g.opentag AS prefix, g.closetag AS suffix
FROM games_champs AS c
LEFT JOIN user AS m ON (m.userid=c.champ_mid)
LEFT JOIN usergroup AS g ON (g.usergroupid=m.usergroupid)
GROUP BY MID 
ORDER BY total DESC LIMIT 3

mySQL error: 
mySQL error code: 
Date: Monday 28th 2019f January 2019 11:47:36 PM

mySQL query error: SELECT c.champ_gid AS GID, c.champ_mid AS MID, c.champ_name AS name, COUNT(c.champ_mid) AS total, g.opentag AS prefix, g.closetag AS suffix
FROM games_champs AS c
LEFT JOIN user AS m ON (m.userid=c.champ_mid)
LEFT JOIN usergroup AS g ON (g.usergroupid=m.usergroupid)
GROUP BY MID 
ORDER BY total DESC LIMIT 3

mySQL error: 
mySQL error code: 
Date: Monday 28th 2019f January 2019 11:47:36 PM

We apologise for any inconvenience

I reupload the files of the product and reinstall the product, but continue the problem.

In admincp-arcade click in Game List, appears this error lines:

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

PHP Warning: A non-numeric value encountered in ..../admincp/arcade.php on line 589

Thanks and regards.

[MrZeropage]

Fine, thanks to stangger!

...and gnrx: don't touch the database again and mess it up

[gnrx]

That I thought at the beginning, that the problem was that "touch" the database, but no ... that was not the problem.
Coincidentally coincided with server migration, and this mod is the only one I have installed (as well as vb) which is, in the configuration of mysql on the server, incompatible with sql_mode = only_full_group_by
So I had to make the appropriate modifications to the mysql configuration for this mod to work.
That's right, until I found out that the problem was that ... I thought it was what I "had touched", xD