Dataform: typenotimplement error when applying a filter search criterion with NOT.

After upgrading to dataform 2.6.4, and when trying to display any view, even without a filter, I got the error message: "error/typenotimplement".

My activity structure is quite simple.
I have one filter, text fields, text area fields and a number field.

More info about this error:

Debug info:
Error code: typenotimplement
$a contents:
Stack trace:
line 749 of /lib/dml/moodle_database.php: dml_exception thrown
line 760 of /mod/dataform/classes/pluginbase/dataformfield.php: call to moodle_database->get_in_or_equal()
line 285 of /mod/dataform/classes/pluginbase/dataformfilter.php: call to mod_dataform\pluginbase\dataformfield->get_search_sql()
line 206 of /mod/dataform/classes/pluginbase/dataformfilter.php: call to mod_dataform\pluginbase\dataformfilter->get_search_sql()
line 224 of /mod/dataform/classes/entry_manager.php: call to mod_dataform\pluginbase\dataformfilter->get_sql()
line 270 of /mod/dataform/classes/entry_manager.php: call to mod_dataform_entry_manager->get_sql_query()
line 133 of /mod/dataform/classes/entry_manager.php: call to mod_dataform_entry_manager->fetch_entries()
line 341 of /mod/dataform/classes/pluginbase/dataformview.php: call to mod_dataform_entry_manager->set_content()
line 324 of /mod/dataform/classes/pluginbase/dataformview.php: call to mod_dataform\pluginbase\dataformview->set_entries_content()
line 404 of /mod/dataform/classes/dataform.php: call to mod_dataform\pluginbase\dataformview->display()
line 70 of /mod/dataform/view.php: call to mod_dataform_dataform->display()