When I upgraded my server to PHP7.2 , I had this issue:
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /path/to/project/vendor/masterexploder/phpthumb/src/PHPThumb/GD.php on line
I found a solution there: https://github.com/masterexploder/PHPThumb/pull/13...
Let's do it
"masterexploder/phpthumb" : "dev-master#9a58407dca8748c3a20bc8143db56aff357bdf91"
Update Composer in SSH
composer updateIt's working now