diff --git a/swad_changelog.h b/swad_changelog.h
index d4b7ed72..bda60f5f 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -231,13 +231,14 @@
 /****************************** Public constants *****************************/
 /*****************************************************************************/
 
-#define Log_PLATFORM_VERSION	"SWAD 16.231 (2017-05-31)"
+#define Log_PLATFORM_VERSION	"SWAD 16.231.1 (2017-05-31)"
 #define CSS_FILE		"swad16.226.css"
 #define JS_FILE			"swad16.206.3.js"
 
 // Number of lines (includes comments but not blank lines) has been got with the following command:
 // nl swad*.c swad*.h css/swad*.css py/swad*.py js/swad*.js soap/swad*?.h sql/swad*.sql | tail -1
 /*
+        Version 16.231.1: May 31, 2017	Fixed bugs in enrolment and groups. (221031 lines)
         Version 16.231:   May 31, 2017	Non-editing teachers can edit (with restrictions) in private zones. (221031 lines)
         Version 16.230:   May 30, 2017	Number of teachers and non-editing teachers in list of groups. (220953 lines)
         Version 16.229.1: May 30, 2017	Code refactoring in selection of groups.
diff --git a/swad_enrolment.c b/swad_enrolment.c
index c1190279..72bd4b27 100644
--- a/swad_enrolment.c
+++ b/swad_enrolment.c
@@ -1846,7 +1846,6 @@ void Enr_AskRemAllStdsThisCrs (void)
    extern const char *Hlp_USERS_Administration_remove_all_students;
    extern const char *Txt_Remove_all_students;
    extern const char *Txt_Do_you_really_want_to_remove_the_X_students_from_the_course_Y_;
-   unsigned NumStds;
 
    /***** Start frame *****/
    Lay_StartRoundFrame (NULL,Txt_Remove_all_students,NULL,
@@ -1857,7 +1856,8 @@ void Enr_AskRemAllStdsThisCrs (void)
       /***** Show question and button to remove students *****/
       /* Start alert */
       sprintf (Gbl.Alert.Txt,Txt_Do_you_really_want_to_remove_the_X_students_from_the_course_Y_,
-               NumStds,Gbl.CurrentCrs.Crs.FullName);
+               Gbl.CurrentCrs.Crs.NumUsrs[Rol_STD],
+               Gbl.CurrentCrs.Crs.FullName);
       Ale_ShowAlertAndButton1 (Ale_QUESTION,Gbl.Alert.Txt);
 
       /* Show form to request confirmation */
diff --git a/swad_group.c b/swad_group.c
index 6bf4fea6..ac7d6ed7 100644
--- a/swad_group.c
+++ b/swad_group.c
@@ -40,10 +40,10 @@
 /*************************** Internal constants ******************************/
 /*****************************************************************************/
 
-#define Grp_GROUP_TYPES_SECTION_ID		"grp_types"
+#define Grp_GROUP_TYPES_SECTION_ID	"grp_types"
 #define Grp_NEW_GROUP_TYPE_SECTION_ID	"new_grp_type"
 #define Grp_GROUPS_SECTION_ID		"grps"
-#define Grp_NEW_GROUP_SECTION_ID		"new_grp"
+#define Grp_NEW_GROUP_SECTION_ID	"new_grp"
 
 /*****************************************************************************/
 /***************************** Internal types ********************************/
@@ -3078,7 +3078,6 @@ bool Grp_GetIfIBelongToGrp (long GrpCod)
       bool IBelongToGrp;
      } Cached =
      {
-      -1L,
       -1L,
       false
      };	// A cache. If this function is called consecutive times