diff --git a/client/message.js b/client/message.js
index 4091023..a963099 100644
--- a/client/message.js
+++ b/client/message.js
@@ -56,6 +56,8 @@ function loadMessages(callback) {
 				let user;
 				if (message.user.name)
 					user = message.user;
+				else if (message.user.id.indexOf('@') === -1)
+					message.user.id = 'deleted user';
 				else {
 					user = users[message.user.id];
 					if (user === undefined)
diff --git a/client/thread.js b/client/thread.js
index 816b7ee..5039db2 100644
--- a/client/thread.js
+++ b/client/thread.js
@@ -14,49 +14,35 @@ function setVisibility() {
 			'only members can post' : 'some members can post'}`;
 }
 
-function chooseThread() {
+function openThread(div, pushState) {
 	if (!document.getElementById('removemember').classList.contains('hidden'))
 		document.getElementById('member').classList.add('hidden');
-	const edit = document.getElementById('edit');
-	let thread = this.thread;
-	let url = new URL(location);
-	if (window.currentThread) {
-		window.currentThread.div.classList.remove('active');
-		let editform = document.getElementById('editthread');
-		if (editform) {
-			editform.remove();
-			edit.textContent = 'edit';
-		}
-		url.searchParams.delete('tab');
-		if (window.currentThread.id === thread.id)
-			url.searchParams.delete('thread');
-		window.history.pushState(null, '', url.toString());
-		if (window.currentThread.id === thread.id) {
-			document.getElementById('thread').classList.add('hidden');
-			window.currentThread = null;
-			return;
-		}
+	if (!div) {
+		document.getElementById('thread').classList.add('hidden');
+		window.currentThread = null;
+		return;
 	}
-	else
-		document.getElementById('thread').classList.remove('hidden');
-	if (thread.permissions.admin) {
+	document.getElementById('thread').classList.remove('hidden');
+	const edit = document.getElementById('edit');
+	if (div.thread.permissions.admin) {
 		edit.classList.remove('hidden');
 		document.getElementById('membersadd').classList.remove('hidden');
 	} else {
 		edit.classList.add('hidden');
 		document.getElementById('membersadd').classList.add('hidden');
 	}
-	document.getElementById('threadname').textContent = thread.name;
-	this.classList.add('active');
-	window.currentThread = thread;
-	window.currentInstance = thread.instance;
-	let div = this;
-	window.currentInstance.emit('get_thread', { thread: thread.id }, async msg => {
+	document.getElementById('threadname').textContent = div.thread.name;
+	if (window.currentThread)
+		window.currentThread.div.classList.remove('active');
+	div.classList.add('active');
+	window.currentThread = div.thread;
+	window.currentInstance = div.thread.instance;
+	window.currentInstance.emit('get_thread', { thread: div.thread.id }, async msg => {
 		if (!msg.success) {
 			console.log('get_thread failed:', msg.message);
 			return;
 		}
-		Object.assign(thread, msg.thread);
+		Object.assign(div.thread, msg.thread);
 		setVisibility();
 		document.getElementById('memberlist').replaceChildren(
 			...await Promise.all(msg.thread.members.map(async member => {
@@ -78,16 +64,11 @@ function chooseThread() {
 			}))
 		);
 		loadCall();
-		let tab = url.searchParams.get('tab');
-		if (!['message', 'space', 'call'].includes(tab))
-			tab = null;
-		if (tab || this.tab) {
-			if (tab)
-				this.tab = tab + 'tab';
-			switchTab(document.getElementById(this.tab));
-			if (this.tab === 'messagetab')
+		if (div.tab) {
+			switchTab(document.getElementById(div.tab));
+			if (div.tab === 'messagetab')
 				loadMessages();
-			else if (this.tab === 'spacetab')
+			else if (div.tab === 'spacetab')
 				loadSpace();
 		}
 		else // load first tab that has any content
@@ -100,27 +81,51 @@ function chooseThread() {
 						loadSpace(spans => {
 							if (spans.length)
 								switchTab(document.getElementById(div.tab = 'spacetab'));
-							else if (window.currentThread.streams.length)
+							else if (Object.keys(currentThread.call).length || currentThread.streams.length)
 								switchTab(document.getElementById(div.tab = 'calltab'));
 							else
 								switchTab(document.getElementById(
 									div.tab = spans.length ? 'spacetab' :
-										window.currentThread.streams.length ? 'calltab' : 'messagetab'));
+										Object.keys(currentThread.call).length || currentThread.streams.length
+											? 'calltab' : 'messagetab'));
 							resolve();
 						});
 				});
 			});
-		if (window.currentInstance === window.instancelist[0]) {
-			url.searchParams.set('thread', thread.id);
-			url.searchParams.set('tab', div.tab.substring(0, div.tab.length - 3));
-		} else {
+		if (pushState) {
+			let url = new URL(window.location);
+			// put instance before thread and tab
 			url.searchParams.delete('thread');
 			url.searchParams.delete('tab');
+			if (currentInstance === instancelist[0])
+				url.searchParams.delete('instance');
+			else
+				url.searchParams.set('instance', currentInstance.url);
+			url.searchParams.set('thread', div.thread.id);
+			url.searchParams.set('tab', div.tab.substring(0, div.tab.length - 3));
+			window.history.pushState(null, '', url.toString());
 		}
-		window.history.pushState(null, '', url.toString());
 	});
 }
 
+window.onpopstate = event => {
+	let params = new URLSearchParams(window.location.search);
+	let thread = params.get('thread');
+	if (!thread) {
+		openThread();
+		return;
+	}
+	let url = params.get('instance');
+	let div = document.querySelector(
+		`#instance${(url ? instancelist.find(i => i.url === url) : instancelist[0])?.id} #thread${thread}`);
+	if (!div)
+		return;
+	let tab = params.get('tab');
+	if (['message', 'space', 'call'].includes(tab))
+		div.tab = tab + 'tab';
+	openThread(div);
+};
+
 function switchTab(tab) {
 	document.querySelectorAll('.tab').forEach(tab => tab.classList.remove('active'));
 	document.querySelectorAll('.tabcontent').forEach(tab => tab.classList.add('hidden'));
@@ -204,8 +209,8 @@ function newThread(instance) {
 					}
 					// since the form exists, this will perform cleanup
 					newThread();
-					chooseThread.call(this.parentElement.parentElement.children['threadlist']
-						.children['thread' + msg.id]);
+					openThread(this.parentElement.parentElement.children['threadlist']
+						.children['thread' + msg.id], true);
 				}
 			);
 		}}>
@@ -366,7 +371,27 @@ async function loadThreads(instancediv, select) {
 	function makeThread(thread) {
 		thread.instance = instancediv.instance;
 		let node = html.node`
-			<div class='thread' onclick=${chooseThread}>${
+			<div class='thread' onclick=${function(event) {
+				let url = new URL(window.location);
+				if (window.currentThread) {
+					let editform = document.getElementById('editthread');
+					if (editform) {
+						editform.remove();
+						edit.textContent = 'edit';
+					}
+					url.searchParams.delete('tab');
+					if (window.currentThread.id === this.thread.id) {
+						openThread();
+						url.searchParams.delete('instance');
+						url.searchParams.delete('thread');
+						window.history.pushState(null, '', url.toString());
+						return;
+					}
+				}
+				else
+					document.getElementById('thread').classList.remove('hidden');
+				openThread(this, true);
+			}}>${
 				thread.name
 			}</div>`;
 		node.id = 'thread' + thread.id;
@@ -434,12 +459,19 @@ async function loadThreads(instancediv, select) {
 
 		instancediv.instance.emit('list_threads', {}, msg => {
 			threadlist.replaceChildren(...msg.threads.map(makeThread));
+			let params = new URLSearchParams(window.location.search);
+			let instance = params.get('instance');
+			instance = instance ? instancelist.find(i => i.url === instance) : instancelist[0];
 			let thread = msg.threads.find(thread =>
-				thread.id == (new URLSearchParams(location.search)).get('thread'))?.div;
-			if (!window.currentThread && thread)
-				chooseThread.call(thread);
+				thread.id == params.get('thread'))?.div;
+			if (thread && (instance === instancediv.instance || !window.currentThread)) {
+				let tab = params.get('tab');
+				if (['message', 'space', 'call'].includes(tab))
+					thread.tab = tab + 'tab';
+				openThread(thread);
+			}
 			else if (select && msg.threads.length)
-				chooseThread.call(threadlist.firstChild);
+				openThread(threadlist.firstChild);
 		});
 
 		instancediv.instance.socket.on('thread', thread => {
diff --git a/server.js b/server.js
index d7b2acc..04b0c41 100644
--- a/server.js
+++ b/server.js
@@ -14,7 +14,7 @@ for (let file of fs.readdirSync('./src/events')) {
 
 function rand32() {
 	let str = '';
-	const lookups = 'abcdefghjklmnpqrstvwxyz0123456789'.split('');
+	const lookups = 'bcdefghjklmnpqrstvwxyz0123456789'.split('');
 	while (str.length < 16) {
 		const n = Math.random() * lookups.length;
 		str += lookups[Math.floor(n)];
diff --git a/src/events/thread.js b/src/events/thread.js
index 39c4a3b..390e35d 100644
--- a/src/events/thread.js
+++ b/src/events/thread.js
@@ -122,6 +122,7 @@ async function create_thread(msg, respond) {
 		streams: [],
 		call: {}
 	};
+	vybe.calls[thread_id] = {};
 	if (!msg.permissions?.view_limited) {
 		for (let id in vybe.users) {
 			for (let socket of vybe.users[id].sockets) {