## change system code
# in the u:OnBeforeItemCreate add line `$object->SetDBField('FirstName', array(1,2,3));` after $object variable is initialized.
# in the users_config php remove `type` key from `FirstName` field configuration (to bypass type validation)
## testing
# go to {nav User Management > Users}
# press `Add` button
# press `Save` button
# confirm that no `strlen() expects parameter 1 to be string, array given` among resulting errors in the debugger