Removed validation from LookupField as it's readonly and just gets in the way of saving data in certain cases

forms/LookupField.php

@@ -79,6 +79,16 @@ class LookupField extends DropdownField {
 		return parent::Field($properties);
 	}
 
+	/**
+	 * Validate this field
+	 *
+	 * @param Validator $validator
+	 * @return bool
+	 */
+	public function validate($validator) {
+		return true;
+	}
+
 	/**
 	 * @return LookupField
 	 */