RenderDataUtil.register(data, "path", file.getPath());
            }).orElse(() -> {
                throwValidationError(messages -> messages.addErrorsFailedToDownloadMappingFile(GLOBAL), this::asDictIndexHtml);
            });
        });
    }

    /**
     * Download a char mapping file.
     * @param form The download form.
     * @return The action response.