Sólo en /srv/limesurvey/limesurvey-3.15-20190228-094129/application/config: config.php
diff -ru application/core/Survey_Common_Action.php /srv/limesurvey/limesurvey-3.15-20190228-094129/application/core/Survey_Common_Action.php
--- application/core/Survey_Common_Action.php	2019-02-14 08:54:53.000000000 -0300
+++ /srv/limesurvey/limesurvey-3.15-20190228-094129/application/core/Survey_Common_Action.php	2019-03-28 11:27:28.554748919 -0300
@@ -1157,7 +1157,7 @@
             if (!empty($ugid)) {
                 $userGroup = UserGroup::model()->findByPk($ugid);
                 $uid = Yii::app()->session['loginID'];
-                if ($userGroup && $userGroup->hasUser($uid)) {
+                if (($userGroup && $userGroup->hasUser($uid)) || Permission::model()->hasGlobalPermission('superadmin') ) {
                     $data['userGroup'] = $userGroup;
                 } else {
                     $data['userGroup'] = null;
diff -ru application/views/admin/usergroup/viewUserGroup_view.php /srv/limesurvey/limesurvey-3.15-20190228-094129/application/views/admin/usergroup/viewUserGroup_view.php
--- application/views/admin/usergroup/viewUserGroup_view.php	2019-02-14 08:54:53.000000000 -0300
+++ /srv/limesurvey/limesurvey-3.15-20190228-094129/application/views/admin/usergroup/viewUserGroup_view.php	2019-03-28 11:17:58.733479788 -0300
@@ -50,7 +50,7 @@
                         <tr class='<?php echo $currentuser["rowclass"];?>'>
                             <td align='center'>
                             <?php
-                            if(isset($currentuser["displayactions"]) && $currentuser["displayactions"] == true && $currentuser["userid"] != '1')
+                            if ( (isset($currentuser["displayactions"]) && $currentuser["displayactions"] == true || Permission::model()->hasGlobalPermission('superadmin')) && $currentuser["userid"] != '1')
                             { ?>
                                 <?php echo CHtml::form(array("admin/usergroups/sa/user/ugid/{$ugid}/action/remove"), 'post'); ?>
                                     <button  data-toggle="tooltip" data-placement="bottom" title="<?php eT('Delete');?>" type="submit" onclick='return confirm("<?php eT("Are you sure you want to delete this entry?","js");?>")' class="btn btn-default btn-xs ">