diff --git a/swad_QR.c b/swad_QR.c
index e9822393..0b2546c4 100644
--- a/swad_QR.c
+++ b/swad_QR.c
@@ -27,6 +27,7 @@
 
 #define _GNU_SOURCE 		// For asprintf
 #include <stdio.h>		// For asprintf
+#include <stdlib.h>		// For free
 
 #include "swad_action.h"
 #include "swad_global.h"
diff --git a/swad_changelog.h b/swad_changelog.h
index 0c8a7b27..99c4d6b9 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -490,7 +490,7 @@ enscript -2 --landscape --color --file-align=2 --highlight --line-numbers -o - *
 En OpenSWAD:
 ps2pdf source.ps destination.pdf
 */
-#define Log_PLATFORM_VERSION	"SWAD 19.51.20 (2019-11-04)"
+#define Log_PLATFORM_VERSION	"SWAD 19.51.21 (2019-11-04)"
 #define CSS_FILE		"swad19.47.css"
 #define JS_FILE			"swad19.39.js"
 /*
@@ -498,7 +498,8 @@ ps2pdf source.ps destination.pdf
 // TODO: Impedir la creación y edición de proyectos si no son editables.
 // TODO: Importante: filtrar proyectos por usuarios (igual que en trabajos o en asistencia)
 
-	Version 19.51.20: Nov 04, 2019	Fixed bug expanding/contracting folders in Microsoft Edge, reported by Mancia Anguita López. (? lines)
+	Version 19.51.21: Nov 04, 2019	Fixed bug in multiple parameter. (245905 lines)
+	Version 19.51.20: Nov 04, 2019	Fixed bug expanding/contracting folders in Microsoft Edge, reported by Mancia Anguita López. (245905 lines)
 	Version 19.51.19: Nov 04, 2019	Code refactoring in HTML inputs. (245904 lines)
 	Version 19.51.18: Nov 04, 2019	Code refactoring in HTML inputs. (245912 lines)
 	Version 19.51.17: Nov 04, 2019	Code refactoring in HTML inputs. (245887 lines)
diff --git a/swad_date.c b/swad_date.c
index 2fd84fc6..a5aa95b8 100644
--- a/swad_date.c
+++ b/swad_date.c
@@ -27,6 +27,7 @@
 
 #define _GNU_SOURCE		// For vasprintf
 #include <stdio.h>		// For vasprintf
+#include <stdlib.h>		// For free
 #include <string.h>		// For string functions
 #include <time.h>		// For time functions (mktime...)
 
diff --git a/swad_logo.c b/swad_logo.c
index 46d65d44..8cfaeba5 100644
--- a/swad_logo.c
+++ b/swad_logo.c
@@ -27,6 +27,7 @@
 
 #define _GNU_SOURCE 		// For asprintf
 #include <stdio.h>		// For asprintf
+#include <stdlib.h>		// For free
 #include <string.h>		// For string functions
 
 #include "swad_action.h"
diff --git a/swad_parameter.c b/swad_parameter.c
index 4bac0cfe..45c6e637 100644
--- a/swad_parameter.c
+++ b/swad_parameter.c
@@ -48,7 +48,7 @@ extern struct Globals Gbl;
 /***************************** Public constants ******************************/
 /*****************************************************************************/
 
-const char *Par_SEPARATOR_PARAM_MULTIPLE = "\0x0A";	// Must be 1 <= character <= 31
+const char *Par_SEPARATOR_PARAM_MULTIPLE = "\x0a";	// Must be 1 <= character <= 31
 
 /*****************************************************************************/
 /*********************** Private types and constants *************************/
diff --git a/swad_test.c b/swad_test.c
index 84523fd8..6003a539 100644
--- a/swad_test.c
+++ b/swad_test.c
@@ -3195,10 +3195,10 @@ void Tst_WriteParamEditQst (void)
   {
    Par_PutHiddenParamChar   ("AllTags",
                              Gbl.Test.Tags.All ? 'Y' :
-                        	                'N');
+                        	                 'N');
    Par_PutHiddenParamString (NULL,"ChkTag",
                              Gbl.Test.Tags.List ? Gbl.Test.Tags.List :
-                        	                 "");
+                        	                  "");
    Par_PutHiddenParamChar   ("AllAnsTypes",
                              Gbl.Test.AllAnsTypes ? 'Y' :
                         	                    'N');