Thanks for help! I think I know the problem ;)

So it appears after I uninstalled and reinstalled, I can't "restore" the following tables to myPHP

sc_thumbs_post
sc_thumbs_visitormessage
sc_thumbs_groupmessage
sc_thumbs_picturecomment
sc_thumbs_picture
sc_thumbs_stats

Provider says my backup tables are innodb and what I currently have is myisam. :confused:

Did you find a solution to this ? Just ran into the same problem.

Yes, but I had to hire a coder and also work with my host provider (I pay for management) to fix the tables. It was a pain in the butt.

I hope you didn't get ripped off because converting tables between engines in a database only takes several minutes. (unless you have millions of records in these tables)

It was a little more complicated as I had this mod "re-modified" for my purposes ;)

Database Error
]]> Database error in vBulletin 4.2.5
Invalid SQL: SELECT * FROM sc_thumbs_post WHERE postid IN () ORDER BY username ASC;

MySQL Error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') ORDER BY username ASC' at line 1
Error Number : 1064
Request Date : Monday, November 11th 2019 @ 05:54:20 AM
Error Date : Monday, November 11th 2019 @ 05:54:20 AM

MySQL Version :
]]>

solved line 109:
$thumbs = $vbulletin->db->query_read("SELECT * FROM " .TABLE_PREFIX. "sc_thumbs_". $contenttype ." WHERE $data_id IN (" . implode(',', $ids) . ") ORDER BY username ASC");

Just as a note. As previous suggestion you need to change line 97 to:

Then line 106 to:

I change back from PHP 7.1 to 7.0 and now the Add work again