Resolved problem... PHP7 to PHP8

from this:

try {
   If ($record [$this-> primaryKey] == '') {
       $record [$this-> primaryKey] = null;
   }
}

to this:

try {
==> if (isset($record[$this->primaryKey])) {
          if ($record[$this->primaryKey] == '') {
             $record[$this->primaryKey] = null;
         }
      }
}

bye