The error appears on my custom grid, where I do 'select all' for all my records (more then 3000) and try to go to the next grid page. As I can see, all my IDS are set into internal_import param of URL
/internal_import_ids/1,2,3,4,5,6,7,8,...
How can I put this internal_import_ids to POST, rather then to URL?
internal_import_ids declared in massaction section
...
$this->getMassactionBlock()->setFormFieldName('import_ids');
...