tweak validation copy

config/locales/en.yml

@@ -171,8 +171,8 @@ en:
       created_by:
         invalid: "Please select owning organisation or managing organisation that you belong to"
       lettype:
-        general_needs_mismatch: Lettings type must be a general needs type
-        supported_housing_mismatch: Lettings type must be a supported housing type
+        general_needs_mismatch: Lettings type must be a general needs type because you selected general needs when uploading the file
+        supported_housing_mismatch: Lettings type must be a supported housing type because you selected supported housing when uploading the file
 
     property:
       mrcdate:

spec/services/bulk_upload/lettings/row_parser_spec.rb

@@ -218,7 +218,7 @@ RSpec.describe BulkUpload::Lettings::RowParser do
           let(:attributes) { { bulk_upload:, field_1: "2" } }
 
           it "is not permitted" do
-            expect(parser.errors[:field_1]).to include("Lettings type must be a general needs type")
+            expect(parser.errors[:field_1]).to include("Lettings type must be a general needs type because you selected general needs when uploading the file")
           end
         end
       end
@@ -230,7 +230,7 @@ RSpec.describe BulkUpload::Lettings::RowParser do
           let(:attributes) { { bulk_upload:, field_1: "1" } }
 
           it "is not permitted" do
-            expect(parser.errors[:field_1]).to include("Lettings type must be a supported housing type")
+            expect(parser.errors[:field_1]).to include("Lettings type must be a supported housing type because you selected supported housing when uploading the file")
           end
         end