diff -r c7c34916027a -r 177826044cd9 wp/wp-admin/includes/ms-deprecated.php
--- a/wp/wp-admin/includes/ms-deprecated.php	Mon Oct 14 18:06:33 2019 +0200
+++ b/wp/wp-admin/includes/ms-deprecated.php	Mon Oct 14 18:28:13 2019 +0200
@@ -16,7 +16,7 @@
  * @deprecated 3.0.0
  */
 function wpmu_menu() {
-	_deprecated_function(__FUNCTION__, '3.0.0' );
+	_deprecated_function( __FUNCTION__, '3.0.0' );
 	// Deprecated. See #11763.
 }
 
@@ -27,10 +27,15 @@
  * @see is_upload_space_available()
  */
 function wpmu_checkAvailableSpace() {
-	_deprecated_function(__FUNCTION__, '3.0.0', 'is_upload_space_available()' );
+	_deprecated_function( __FUNCTION__, '3.0.0', 'is_upload_space_available()' );
 
-	if ( !is_upload_space_available() )
-		wp_die( __('Sorry, you must delete files before you can upload any more.') );
+	if ( ! is_upload_space_available() ) {
+		wp_die( sprintf(
+			/* translators: %s: allowed space allocation */
+			__( 'Sorry, you have used your space allocation of %s. Please delete some files to upload more files.' ),
+			size_format( get_space_allowed() * MB_IN_BYTES )
+		) );
+	}
 }
 
 /**
@@ -39,7 +44,7 @@
  * @deprecated 3.0.0
  */
 function mu_options( $options ) {
-	_deprecated_function(__FUNCTION__, '3.0.0' );
+	_deprecated_function( __FUNCTION__, '3.0.0' );
 	return $options;
 }
 
@@ -50,7 +55,7 @@
  * @see activate_plugin()
  */
 function activate_sitewide_plugin() {
-	_deprecated_function(__FUNCTION__, '3.0.0', 'activate_plugin()' );
+	_deprecated_function( __FUNCTION__, '3.0.0', 'activate_plugin()' );
 	return false;
 }
 
@@ -61,7 +66,7 @@
  * @see deactivate_plugin()
  */
 function deactivate_sitewide_plugin( $plugin = false ) {
-	_deprecated_function(__FUNCTION__, '3.0.0', 'deactivate_plugin()' );
+	_deprecated_function( __FUNCTION__, '3.0.0', 'deactivate_plugin()' );
 }
 
 /**
@@ -71,7 +76,7 @@
  * @see is_network_only_plugin()
  */
 function is_wpmu_sitewide_plugin( $file ) {
-	_deprecated_function(__FUNCTION__, '3.0.0', 'is_network_only_plugin()' );
+	_deprecated_function( __FUNCTION__, '3.0.0', 'is_network_only_plugin()' );
 	return is_network_only_plugin( $file );
 }