"The SharePoint list form can't be customized with InfoPath because fields of an unsupported data type are marked as required, or because fields are corrupted. In SharePoint, try deleting the columns or editing the column properties to remove the required attribute.
- my_fieldname (Lookup)" IN the field in infopath it says "the lookup field is not valid because the reference list or list column does not exist. delete the field and recreate it."