diff --git a/public/src/app.js b/public/src/app.js
index 913360c615..421cf71943 100644
--- a/public/src/app.js
+++ b/public/src/app.js
@@ -439,6 +439,9 @@ app.cacheBuster = null;
 				.replace('{pageTitle}', function () { return title; })
 				.replace('{browserTitle}', function () { return config.browserTitle; });
 
+			// Allow translation strings in title on ajaxify (#5927)
+			title = translator.unescape(title);
+
 			translator.translate(title, function (translated) {
 				titleObj.titles[0] = translated;
 				app.alternatingTitle('');
diff --git a/src/controllers/errors.js b/src/controllers/errors.js
index 177bcaa769..96bfda203c 100644
--- a/src/controllers/errors.js
+++ b/src/controllers/errors.js
@@ -3,6 +3,7 @@
 var nconf = require('nconf');
 var winston = require('winston');
 var validator = require('validator');
+var plugins = require('../plugins');
 
 exports.handleURIErrors = function (err, req, res, next) {
 	// Handle cases where malformed URIs are passed in
@@ -35,30 +36,50 @@ exports.handleURIErrors = function (err, req, res, next) {
 // this needs to have four arguments or express treats it as `(req, res, next)`
 // don't remove `next`!
 exports.handleErrors = function (err, req, res, next) { // eslint-disable-line no-unused-vars
-	switch (err.code) {
-	case 'EBADCSRFTOKEN':
-		winston.error(req.path + '\n', err.message);
-		return res.sendStatus(403);
-	case 'blacklisted-ip':
-		return res.status(403).type('text/plain').send(err.message);
-	}
+	var cases = {
+		EBADCSRFTOKEN: function () {
+			winston.error(req.path + '\n', err.message);
+			res.sendStatus(403);
+		},
+		'blacklisted-ip': function () {
+			res.status(403).type('text/plain').send(err.message);
+		},
+	};
+	var defaultHandler = function () {
+		// Display NodeBB error page
+		var status = parseInt(err.status, 10);
+		if ((status === 302 || status === 308) && err.path) {
+			return res.locals.isAPI ? res.set('X-Redirect', err.path).status(200).json(err.path) : res.redirect(err.path);
+		}
 
-	var status = parseInt(err.status, 10);
-	if ((status === 302 || status === 308) && err.path) {
-		return res.locals.isAPI ? res.set('X-Redirect', err.path).status(200).json(err.path) : res.redirect(err.path);
-	}
+		winston.error(req.path + '\n', err.stack);
 
-	winston.error(req.path + '\n', err.stack);
+		res.status(status || 500);
 
-	res.status(status || 500);
+		var path = String(req.path || '');
+		if (res.locals.isAPI) {
+			res.json({ path: validator.escape(path), error: err.message });
+		} else {
+			var middleware = require('../middleware');
+			middleware.buildHeader(req, res, function () {
+				res.render('500', { path: validator.escape(path), error: validator.escape(String(err.message)) });
+			});
+		}
+	};
 
-	var path = String(req.path || '');
-	if (res.locals.isAPI) {
-		res.json({ path: validator.escape(path), error: err.message });
-	} else {
-		var middleware = require('../middleware');
-		middleware.buildHeader(req, res, function () {
-			res.render('500', { path: validator.escape(path), error: validator.escape(String(err.message)) });
-		});
-	}
+	plugins.fireHook('filter:error.handle', {
+		cases: cases,
+	}, function (_err, data) {
+		if (_err) {
+			// Assume defaults
+			winston.warn('[errors/handle] Unable to retrieve plugin handlers for errors: ' + _err.message);
+			data.cases = cases;
+		}
+
+		if (data.cases.hasOwnProperty(err.code)) {
+			data.cases[err.code](err, req, res, defaultHandler);
+		} else {
+			defaultHandler();
+		}
+	});
 };
diff --git a/src/meta/blacklist.js b/src/meta/blacklist.js
index 31af5f9eee..d872f3ee07 100644
--- a/src/meta/blacklist.js
+++ b/src/meta/blacklist.js
@@ -20,7 +20,7 @@ Blacklist.load = function (callback) {
 		Blacklist.get,
 		Blacklist.validate,
 		function (rules, next) {
-			winston.verbose('[meta/blacklist] Loading ' + rules.valid.length + ' blacklist rules');
+			winston.verbose('[meta/blacklist] Loading ' + rules.valid.length + ' blacklist rule(s)' + (rules.duplicateCount > 0 ? ', ignored ' + rules.duplicateCount + ' duplicate(s)' : ''));
 			if (rules.invalid.length) {
 				winston.warn('[meta/blacklist] ' + rules.invalid.length + ' invalid blacklist rule(s) were ignored.');
 			}
@@ -44,8 +44,8 @@ Blacklist.save = function (rules, callback) {
 			db.setObject('ip-blacklist-rules', { rules: rules }, next);
 		},
 		function (next) {
-			Blacklist.load(next);
 			pubsub.publish('blacklist:reload');
+			setImmediate(next);
 		},
 	], callback);
 };
@@ -111,6 +111,7 @@ Blacklist.validate = function (rules, callback) {
 	var ipv6 = [];
 	var cidr = [];
 	var invalid = [];
+	var duplicateCount = 0;
 
 	var inlineCommentMatch = /#.*$/;
 	var whitelist = ['127.0.0.1', '::1', '::ffff:0:127.0.0.1'];
@@ -122,6 +123,16 @@ Blacklist.validate = function (rules, callback) {
 		return rule.length && !rule.startsWith('#') ? rule : null;
 	}).filter(Boolean);
 
+	// Filter out duplicates
+	rules = rules.filter(function (rule, index) {
+		const pass = rules.indexOf(rule) === index;
+		if (!pass) {
+			duplicateCount += 1;
+		}
+
+		return pass;
+	});
+
 	// Filter out invalid rules
 	rules = rules.filter(function (rule) {
 		var addr;
@@ -167,6 +178,7 @@ Blacklist.validate = function (rules, callback) {
 		cidr: cidr,
 		valid: rules,
 		invalid: invalid,
+		duplicateCount: duplicateCount,
 	});
 };
 
diff --git a/src/middleware/index.js b/src/middleware/index.js
index 507878dc0c..d5f7e5e6a3 100644
--- a/src/middleware/index.js
+++ b/src/middleware/index.js
@@ -9,6 +9,7 @@ var nconf = require('nconf');
 var ensureLoggedIn = require('connect-ensure-login');
 var toobusy = require('toobusy-js');
 var Benchpress = require('benchpressjs');
+var LRU = require('lru-cache');
 
 var plugins = require('../plugins');
 var meta = require('../meta');
@@ -23,6 +24,10 @@ var controllers = {
 	helpers: require('../controllers/helpers'),
 };
 
+var delayCache = LRU({
+	maxAge: 1000 * 60,
+});
+
 var middleware = module.exports;
 
 middleware.applyCSRF = csrf();
@@ -186,6 +191,14 @@ middleware.processTimeagoLocales = function (req, res, next) {
 
 middleware.delayLoading = function (req, res, next) {
 	// Introduces an artificial delay during load so that brute force attacks are effectively mitigated
+
+	// Add IP to cache so if too many requests are made, subsequent requests are blocked for a minute
+	var timesSeen = delayCache.get(req.ip) || 0;
+	if (timesSeen > 10) {
+		return res.sendStatus(429);
+	}
+	delayCache.set(req.ip, timesSeen += 1);
+
 	setTimeout(next, 1000);
 };
 
diff --git a/src/views/500-embed.tpl b/src/views/500-embed.tpl
index f5258cb8db..d9d9f30d5d 100644
--- a/src/views/500-embed.tpl
+++ b/src/views/500-embed.tpl
@@ -1,12 +1,14 @@
 <script>
-define('/assets/templates/500.js', function () {
-	function compiled(helpers, context, get, iter, helper) {
-		return '<div class="alert alert-danger">\n\t<strong>[[global:500.title]]</strong>\n\t<p>[[global:500.message]]</p>\n\t<p>' + 
-    		helpers.__escape(get(context && context['path'])) + '</p>\n\t' + 
-			(get(context && context['error']) ? '<p>' + helpers.__escape(get(context && context['error'])) + '</p>' : '') + '\n\n\t' + 
-			(get(context && context['returnLink']) ? '\n\t<p>[[error:goback]]</p>\n\t' : '') + '\n</div>\n';
-	}
+	window.addEventListener('load', function () {
+		define('/assets/templates/500.js', function () {
+			function compiled(helpers, context, get, iter, helper) {
+				return '<div class="alert alert-danger">\n\t<strong>[[global:500.title]]</strong>\n\t<p>[[global:500.message]]</p>\n\t<p>' + 
+					helpers.__escape(get(context && context['path'])) + '</p>\n\t' + 
+					(get(context && context['error']) ? '<p>' + helpers.__escape(get(context && context['error'])) + '</p>' : '') + '\n\n\t' + 
+					(get(context && context['returnLink']) ? '\n\t<p>[[error:goback]]</p>\n\t' : '') + '\n</div>\n';
+			}
 
-	return compiled;
-});
+			return compiled;
+		});
+	});
 </script>
\ No newline at end of file
diff --git a/src/webserver.js b/src/webserver.js
index 2918ea12f7..6f89ea8570 100644
--- a/src/webserver.js
+++ b/src/webserver.js
@@ -180,8 +180,15 @@ function setupExpressApp(app, callback) {
 	setupAutoLocale(app, callback);
 }
 
-function ping(req, res) {
-	res.status(200).send(req.path === '/sping' ? 'healthy' : '200');
+function ping(req, res, next) {
+	async.waterfall([
+		function (next) {
+			db.getObject('config', next);
+		},
+		function () {
+			res.status(200).send(req.path === '/sping' ? 'healthy' : '200');
+		},
+	], next);
 }
 
 function setupFavicon(app) {