A bit more evident that the feature is now active or not

Themes/core/css/index.css

@@ -2743,7 +2743,7 @@ dl
 }
 
 /* Simple feedback messages */
-div#profile_error, div#profile_success
+div#profile_error, div#profile_success, div.successbox
 {
 	margin: 0 0 1em 0;
 	padding: 1em 2em;
@@ -2761,7 +2761,7 @@ div#profile_error span
 	text-decoration: underline;
 }
 
-div#profile_success
+div#profile_success, div.successbox
 {
 	border-color: green;
 	color: green;

Themes/default/Admin.template.php

@@ -1339,23 +1339,31 @@ function template_core_features()
 					// The type of data that is getting returned.
 					data: data,
 					error: function(error){
-							$("#activation_errors").html(error).slideDown(\'fast\');
+							$("#activation_message").html(error).slideDown(\'fast\');
 					},
 
 					success: function(request){
 						if ($(request).find("errors").find("error").length != 0)
 						{
-							$("#activation_errors").html($(request).find("errors").find("error").text()).slideDown(\'fast\');
+							$("#activation_message").html($(request).find("errors").find("error").text()).slideDown(\'fast\');
 						}
-						else
+						else if ($(request).find("smf").length != 0)
 						{
 							$("#feature_link_" + cf).html($(request).find("corefeatures").find("corefeature").text());
 							cc.attr("src", imgs[new_state ? 1 : 0]);
 							$("#feature_link_" + cf).fadeOut().fadeIn();
+							$("#activation_message").attr(\'class\', \'successbox\');
+							var message = new_state ? ' . JavaScriptEscape($txt['core_settings_activation_message']) . ' : ' . JavaScriptEscape($txt['core_settings_deactivation_message']) . ';
+							$("#activation_message").html(message.replace(\'{core_feature}\', $(request).find("corefeatures").find("corefeature").text())).slideDown(\'fast\').fadeOut().fadeIn();;
 
 							token_name = $(request).find("tokens").find(\'[type="token"]\').text();
 							token_value = $(request).find("tokens").find(\'[type="token_var"]\').text();
 						}
+						else
+						{
+							$("#activation_message").html(' . JavaScriptEscape($txt['core_settings_generic_error']) . ').slideDown(\'fast\');
+							
+						}
 					}
 				});
 			});
@@ -1382,7 +1390,7 @@ function template_core_features()
 					', $txt['core_settings_title'], '
 				</h3>
 			</div>
-			<div style="display:none" id="activation_errors" class="errorbox"></div>';
+			<div style="display:none" id="activation_message" class="errorbox"></div>';
 
 	$alternate = true;
 	foreach ($context['features'] as $id => $feature)

Themes/default/css/compat.css

@@ -1697,7 +1697,7 @@ dl
 }
 
 /* Simple feedback messages */
-div#profile_error, div#profile_success
+div#profile_error, div#profile_success, div.successbox
 {
 	margin: 0 0 1em 0;
 	padding: 1em 2em;
@@ -1715,7 +1715,7 @@ div#profile_error span
 	text-decoration: underline;
 }
 
-div#profile_success
+div#profile_success, div.successbox
 {
 	border-color: green;
 	color: green;

Themes/default/css/index.css

@@ -2949,7 +2949,7 @@ dl
 }
 
 /* Simple feedback messages */
-div#profile_error, div#profile_success
+div#profile_error, div#profile_success, div.successbox
 {
 	margin: 0 0 1em 0;
 	padding: 1em 2em;
@@ -2967,7 +2967,7 @@ div#profile_error span
 	text-decoration: underline;
 }
 
-div#profile_success
+div#profile_success, div.successbox
 {
 	border-color: green;
 	color: green;

Themes/default/languages/Admin.english.php

@@ -578,6 +578,10 @@ $txt['signature_settings_short'] = 'Signatures';
 $txt['custom_profile_shorttitle'] = 'Profile Fields';
 $txt['pruning_title'] = 'Log Pruning';
 
+$txt['core_settings_activation_message'] = 'The Feature {core_feature} has been activated, click on the title to configure it';
+$txt['core_settings_deactivation_message'] = 'The Feature {core_feature} has been deactivated';
+$txt['core_settings_generic_error'] = 'An unforeseen error occurred, please relod the page and try again';
+
 $txt['boardsEdit'] = 'Modify Boards';
 $txt['mboards_new_cat'] = 'Create New Category';
 $txt['manage_holidays'] = 'Manage Holidays';