Hi,
Thank you. That's much more clear. I was able to reproduce the problem on my end and fix it.
Change the line:
$output .= ' <input class="inputbox" type="text" name="filter['.$table->table.']['.$key.']['.$column.'][value]" size="50" value="'.$value->data['value'].'" onchange="countresults(\''.$table->table.'\',\''.$key.'\')" />';
to:
$output .= ' <input class="inputbox" type="text" name="filter['.$table->table.']['.$key.']['.$column.'][value]" size="50" value="'.htmlspecialchars($value->data['value'], ENT_COMPAT, 'UTF-8').'" onchange="countresults(\''.$table->table.'\',\''.$key.'\')" />';
in plugins/system/hikashopmassaction/hikashopmassaction.php and that will fix the problem. We'll add that patch on our end too.