diff --git a/swad_attendance.c b/swad_attendance.c
index c090d106a..f7bb929c4 100644
--- a/swad_attendance.c
+++ b/swad_attendance.c
@@ -1935,7 +1935,7 @@ static void Att_ListAttStudents (struct AttendanceEvent *Att)
                  Hlp_USERS_Attendance,Box_NOT_CLOSABLE);
 
    /***** Form to select groups *****/
-   Grp_ShowFormToSelectSeveralGroups (ActSeeOneAtt);
+   Grp_ShowFormToSelectSeveralGroups (ActSeeOneAtt,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
@@ -2672,7 +2672,7 @@ void Usr_ReqListStdsAttendanceCrs (void)
 		 Hlp_USERS_Attendance_attendance_list,Box_NOT_CLOSABLE);
 
    /***** Form to select groups *****/
-   Grp_ShowFormToSelectSeveralGroups (ActReqLstStdAtt);
+   Grp_ShowFormToSelectSeveralGroups (ActReqLstStdAtt,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
diff --git a/swad_changelog.h b/swad_changelog.h
index ebf7e8c4f..89aaa80df 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -236,13 +236,14 @@
 /****************************** Public constants *****************************/
 /*****************************************************************************/
 
-#define Log_PLATFORM_VERSION	"SWAD 16.247 (2017-06-20)"
+#define Log_PLATFORM_VERSION	"SWAD 16.247.1 (2017-06-23)"
 #define CSS_FILE		"swad16.235.1.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 16.247.1: Jun 23, 2017	Non-editing teachers can select all groups when writing a message. (222068 lines)
         Version 16.247:   Jun 20, 2017	Fixed bug when removing a user from a course.
 					Code refactoring related with caches. (222063 lines)
         Version 16.246:   Jun 20, 2017	Fixed bugs and code refactoring in groups. (221975 lines)
diff --git a/swad_file_browser.c b/swad_file_browser.c
index 198f618d1..e1ee90d88 100644
--- a/swad_file_browser.c
+++ b/swad_file_browser.c
@@ -3124,7 +3124,7 @@ void Brw_AskEditWorksCrs (void)
                  Hlp_FILES_Homework_for_teachers,Box_NOT_CLOSABLE);
 
    /***** Show form to select the groups *****/
-   Grp_ShowFormToSelectSeveralGroups (ActReqAsgWrkCrs);
+   Grp_ShowFormToSelectSeveralGroups (ActReqAsgWrkCrs,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
diff --git a/swad_group.c b/swad_group.c
index ef9692e5d..d2fa1ef77 100644
--- a/swad_group.c
+++ b/swad_group.c
@@ -90,7 +90,7 @@ static void Grp_EditGroups (void);
 static void Grp_PutIconsEditingGroups (void);
 static void Grp_PutIconToCreateNewGroup (void);
 
-static void Grp_PutCheckboxAllGrps (void);
+static void Grp_PutCheckboxAllGrps (bool AllGroupsSelectable);
 
 static void Grp_ConstructorListGrpAlreadySelec (struct ListGrpsAlreadySelec **AlreadyExistsGroupOfType);
 static void Grp_DestructorListGrpAlreadySelec (struct ListGrpsAlreadySelec **AlreadyExistsGroupOfType);
@@ -111,7 +111,8 @@ static void Grp_ShowWarningToStdsToChangeGrps (void);
 static bool Grp_ListGrpsForChangeMySelection (struct GroupType *GrpTyp,
                                               unsigned *NumGrpsThisTypeIBelong);
 static void Grp_ListGrpsToAddOrRemUsrs (struct GroupType *GrpTyp,long UsrCod);
-static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp);
+static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp,
+                                              bool AllGroupsSelectable);
 static void Grp_WriteGrpHead (struct GroupType *GrpTyp);
 static void Grp_WriteRowGrp (struct Group *Grp,bool Highlight);
 static void Grp_PutFormToCreateGroupType (void);
@@ -346,7 +347,7 @@ static void Grp_PutIconToCreateNewGroup (void)
 /*************** Show form to select one or several groups *******************/
 /*****************************************************************************/
 
-void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction)
+void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction,bool AllGroupsSelectable)
   {
    extern const char *Hlp_USERS_Groups;
    extern const char *The_ClassFormBold[The_NUM_THEMES];
@@ -376,7 +377,7 @@ void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction)
       Usr_PutExtraParamsUsrList (NextAction);
 
       /***** Select all groups *****/
-      Grp_PutCheckboxAllGrps ();
+      Grp_PutCheckboxAllGrps (AllGroupsSelectable);
 
       /***** Get list of groups types and groups in this course *****/
       Grp_GetListGrpTypesAndGrpsInThisCrs (Grp_ONLY_GROUP_TYPES_WITH_GROUPS);
@@ -387,7 +388,8 @@ void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction)
 	   NumGrpTyp < Gbl.CurrentCrs.Grps.GrpTypes.Num;
 	   NumGrpTyp++)
 	 if (Gbl.CurrentCrs.Grps.GrpTypes.LstGrpTypes[NumGrpTyp].NumGrps)
-	    Grp_ListGrpsForMultipleSelection (&Gbl.CurrentCrs.Grps.GrpTypes.LstGrpTypes[NumGrpTyp]);
+	    Grp_ListGrpsForMultipleSelection (&Gbl.CurrentCrs.Grps.GrpTypes.LstGrpTypes[NumGrpTyp],
+	                                      AllGroupsSelectable);
       Tbl_EndTable ();
 
       /***** Free list of groups types and groups in this course *****/
@@ -415,7 +417,7 @@ void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction)
 /******************* Put checkbox to select all groups ***********************/
 /*****************************************************************************/
 
-static void Grp_PutCheckboxAllGrps (void)
+static void Grp_PutCheckboxAllGrps (bool AllGroupsSelectable)
   {
    extern const char *The_ClassForm[The_NUM_THEMES];
    extern const char *Txt_All_groups;
@@ -424,7 +426,7 @@ static void Grp_PutCheckboxAllGrps (void)
    switch (Gbl.Usrs.Me.Role.Logged)
      {
       case Rol_NET:
-	 ICanSelUnselGroup = false;
+	 ICanSelUnselGroup = AllGroupsSelectable;
 	 break;
       case Rol_STD:
       case Rol_TCH:
@@ -2128,7 +2130,8 @@ static void Grp_ListGrpsToAddOrRemUsrs (struct GroupType *GrpTyp,long UsrCod)
 /******* Write a list of groups as checkbox form for unique selection ********/
 /*****************************************************************************/
 
-static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp)
+static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp,
+                                              bool AllGroupsSelectable)
   {
    extern const char *Txt_users_with_no_group;
    unsigned NumGrpThisType;
@@ -2164,7 +2167,8 @@ static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp)
 	 switch (Gbl.Usrs.Me.Role.Logged)
 	   {
 	    case Rol_NET:
-	       ICanSelUnselGroup = IBelongToThisGroup;
+	       ICanSelUnselGroup = AllGroupsSelectable ||
+	                           IBelongToThisGroup;
 	       break;
 	    case Rol_STD:
 	    case Rol_TCH:
diff --git a/swad_group.h b/swad_group.h
index 12bc3ab82..a9965150c 100644
--- a/swad_group.h
+++ b/swad_group.h
@@ -135,7 +135,7 @@ typedef enum
 void Grp_WriteNamesOfSelectedGrps (void);
 void Grp_ReqEditGroups (void);
 
-void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction);
+void Grp_ShowFormToSelectSeveralGroups (Act_Action_t NextAction,bool AllGroupsSelectable);
 void Grp_PutParamsCodGrps (void);
 void Grp_GetParCodsSeveralGrpsToShowUsrs (void);
 void Grp_GetParCodsSeveralGrps (void);
diff --git a/swad_mail.c b/swad_mail.c
index a9a5e4fcd..37641ea30 100644
--- a/swad_mail.c
+++ b/swad_mail.c
@@ -892,7 +892,7 @@ void Mai_ListEmails (void)
 		 Hlp_MESSAGES_Email,Box_NOT_CLOSABLE);
 
    /***** Form to select groups *****/
-   Grp_ShowFormToSelectSeveralGroups (ActMaiStd);
+   Grp_ShowFormToSelectSeveralGroups (ActMaiStd,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
diff --git a/swad_message.c b/swad_message.c
index bc2779d9e..f92b47209 100644
--- a/swad_message.c
+++ b/swad_message.c
@@ -238,7 +238,7 @@ static void Msg_PutFormMsgUsrs (char Content[Cns_MAX_BYTES_LONG_TEXT + 1])
       if (GetUsrsInCrs)
 	{
 	 /***** Form to select groups *****/
-	 Grp_ShowFormToSelectSeveralGroups (ActReqMsgUsr);
+	 Grp_ShowFormToSelectSeveralGroups (ActReqMsgUsr,true);
 
 	 /***** Start section with user list *****/
          Lay_StartSection (Usr_USER_LIST_SECTION_ID);
diff --git a/swad_statistic.c b/swad_statistic.c
index e68c7223a..d77f8c874 100644
--- a/swad_statistic.c
+++ b/swad_statistic.c
@@ -480,7 +480,7 @@ void Sta_AskShowCrsHits (void)
                  Hlp_STATS_Visits_visits_to_course,Box_NOT_CLOSABLE);
 
    /***** Show form to select the groups *****/
-   Grp_ShowFormToSelectSeveralGroups (ActReqAccCrs);
+   Grp_ShowFormToSelectSeveralGroups (ActReqAccCrs,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
diff --git a/swad_test.c b/swad_test.c
index 020967f10..6ee7affb0 100644
--- a/swad_test.c
+++ b/swad_test.c
@@ -6986,7 +6986,7 @@ void Tst_SelUsrsToSeeUsrsTestResults (void)
                  Hlp_ASSESSMENT_Tests_test_results,Box_NOT_CLOSABLE);
 
    /***** Show form to select the groups *****/
-   Grp_ShowFormToSelectSeveralGroups (ActReqSeeUsrTstRes);
+   Grp_ShowFormToSelectSeveralGroups (ActReqSeeUsrTstRes,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
diff --git a/swad_user.c b/swad_user.c
index a2d9bc084..222f08823 100644
--- a/swad_user.c
+++ b/swad_user.c
@@ -7403,7 +7403,7 @@ void Usr_SeeStudents (void)
 
    /***** Form to select groups *****/
    if (Gbl.Scope.Current == Sco_SCOPE_CRS)
-      Grp_ShowFormToSelectSeveralGroups (ActLstStd);
+      Grp_ShowFormToSelectSeveralGroups (ActLstStd,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);
@@ -7578,7 +7578,7 @@ void Usr_SeeTeachers (void)
 
    /***** Form to select groups *****/
    if (Gbl.Scope.Current == Sco_SCOPE_CRS)
-      Grp_ShowFormToSelectSeveralGroups (ActLstTch);
+      Grp_ShowFormToSelectSeveralGroups (ActLstTch,false);
 
    /***** Start section with user list *****/
    Lay_StartSection (Usr_USER_LIST_SECTION_ID);