diff --git a/install/dist/lib/fedora.lib.php b/install/dist/lib/fedora.lib.php
index 66cddd88400206374a97a85d9b011070d9698e5a..6cb47183d95dc9ee13e73651e67630db4364de88 100644
--- a/install/dist/lib/fedora.lib.php
+++ b/install/dist/lib/fedora.lib.php
@@ -857,17 +857,23 @@ class installer_dist extends installer_base {
 		if($conf['apache']['installed'] == true){
 			$command = 'usermod -a -G ispconfig '.$conf['apache']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'usermod -a -G ispapps '.$conf['apache']['user'];
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'usermod -a -G ispapps '.$conf['apache']['user'];
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		if($conf['nginx']['installed'] == true){
 			$command = 'usermod -a -G ispconfig '.$conf['nginx']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			// Allow the ispapps vhost access to /etc/squirrelmail
-			$command = 'usermod -a -G '.$conf['apache']['group'].' ispapps';
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'usermod -a -G ispapps '.$conf['nginx']['user'];
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_user('ispapps')){
+				// Allow the ispapps vhost access to /etc/squirrelmail
+				$command = 'usermod -a -G '.$conf['apache']['group'].' ispapps';
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
+			if(is_group('ispapps')){
+				$command = 'usermod -a -G ispapps '.$conf['nginx']['user'];
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		
 		//* Make the shell scripts executable
diff --git a/install/dist/lib/gentoo.lib.php b/install/dist/lib/gentoo.lib.php
index 55626ec8c4c59b696a36de23c9e1743aa8729025..5aa5de18ff5c28339a69a73a4ac85d2abeee65cc 100644
--- a/install/dist/lib/gentoo.lib.php
+++ b/install/dist/lib/gentoo.lib.php
@@ -870,14 +870,18 @@ class installer extends installer_base
 		if($conf['apache']['installed'] == true){
 			$command = 'usermod -a -G ispconfig '.$conf['apache']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'usermod -a -G ispapps '.$conf['apache']['user'];
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'usermod -a -G ispapps '.$conf['apache']['user'];
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		if($conf['nginx']['installed'] == true){
 			$command = 'usermod -a -G ispconfig '.$conf['nginx']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'usermod -a -G ispapps '.$conf['nginx']['user'];
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'usermod -a -G ispapps '.$conf['nginx']['user'];
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		
 		//* Make the shell scripts executable
diff --git a/install/dist/lib/opensuse.lib.php b/install/dist/lib/opensuse.lib.php
index fbf4c68e0476d3a72b35c0594d94d90ce80fd09e..22438cc59feede6296477d816c70825dada7bce7 100644
--- a/install/dist/lib/opensuse.lib.php
+++ b/install/dist/lib/opensuse.lib.php
@@ -894,14 +894,18 @@ class installer_dist extends installer_base {
 		if($conf['apache']['installed'] == true){
 			$command = 'groupmod --add-user '.$conf['apache']['user'].' ispconfig';
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'groupmod --add-user '.$conf['apache']['user'].' ispapps';
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'groupmod --add-user '.$conf['apache']['user'].' ispapps';
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		if($conf['nginx']['installed'] == true){
 			$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispconfig';
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispapps';
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispapps';
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		
 		//* Make the shell scripts executable
diff --git a/install/lib/installer_base.lib.php b/install/lib/installer_base.lib.php
index 6b1f4ee143667e3b2a7e71e584b5f16dfc991d43..fcd8673f638029bb5ff45f176f2843393fd68c34 100644
--- a/install/lib/installer_base.lib.php
+++ b/install/lib/installer_base.lib.php
@@ -1752,14 +1752,18 @@ class installer_base {
 		if($conf['apache']['installed'] == true){
 			$command = 'adduser '.$conf['apache']['user'].' ispconfig';
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'adduser '.$conf['apache']['user'].' ispapps';
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'adduser '.$conf['apache']['user'].' ispapps';
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 		if($conf['nginx']['installed'] == true){
 			$command = 'adduser '.$conf['nginx']['user'].' ispconfig';
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
-			$command = 'adduser '.$conf['nginx']['user'].' ispapps';
-			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			if(is_group('ispapps')){
+				$command = 'adduser '.$conf['nginx']['user'].' ispapps';
+				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
+			}
 		}
 
 		//* Make the shell scripts executable