diff --git a/extension/contextmenu/colormode.js b/extension/contextmenu/colormode.js
index afababa2..39261a87 100644
--- a/extension/contextmenu/colormode.js
+++ b/extension/contextmenu/colormode.js
@@ -22,16 +22,24 @@ var platform = typeof browser === 'undefined'
   ? chrome
   : browser
 
-const sendColorMode = () => {
-  platform.tabs.query({active: true, currentWindow: true}, ([tab]) => {
-    tab && platform.tabs.sendMessage(tab.id, {
+const sendColorMode = tab_id => {
+  if (tab_id === undefined) return
+
+  try {
+    const pending_message = platform.tabs.sendMessage(tab_id, {
       action: 'COLOR_MODE',
       params: {mode:colormodestate.mode},
     })
-  })
+
+    // The tab can navigate or close before the message is delivered.
+    pending_message?.catch?.(() => undefined)
+  }
+  catch {
+    // Callback-based browser implementations throw instead of returning a promise.
+  }
 }
 
-export const getColorMode = () => {
+export const getColorMode = tab_id => {
   platform.storage.sync.get([storagekey], value => {
     let found_value = value[storagekey]
 
@@ -64,7 +72,7 @@ export const getColorMode = () => {
 
     // send visbug user preference
     colormodestate.mode = found_value
-    sendColorMode()
+    sendColorMode(tab_id)
 
     return found_value
   })
@@ -96,5 +104,5 @@ platform.contextMenus.onClicked.addListener(({parentMenuItemId, menuItemId}, tab
   platform.storage.sync.set({[storagekey]: menuItemId})
   colormodestate.mode = menuItemId
 
-  sendColorMode()
+  sendColorMode(tab?.id)
 })
diff --git a/extension/contextmenu/colorscheme.js b/extension/contextmenu/colorscheme.js
index 8bae16b7..a88a4b0c 100644
--- a/extension/contextmenu/colorscheme.js
+++ b/extension/contextmenu/colorscheme.js
@@ -15,16 +15,24 @@ var platform = typeof browser === 'undefined'
   ? chrome
   : browser
 
-const sendColorScheme = () => {
-  platform.tabs.query({active: true, currentWindow: true}, ([tab]) => {
-    tab && platform.tabs.sendMessage(tab.id, {
+const sendColorScheme = tab_id => {
+  if (tab_id === undefined) return
+
+  try {
+    const pending_message = platform.tabs.sendMessage(tab_id, {
       action: 'COLOR_SCHEME',
       params: {mode:colorschemestate.mode},
     })
-  })
+
+    // The tab can navigate or close before the message is delivered.
+    pending_message?.catch?.(() => undefined)
+  }
+  catch {
+    // Callback-based browser implementations throw instead of returning a promise.
+  }
 }
 
-export const getColorScheme = () => {
+export const getColorScheme = tab_id => {
   platform.storage.sync.get([schemestoragekey], value => {
     let found_value = value[schemestoragekey];
 
@@ -43,7 +51,7 @@ export const getColorScheme = () => {
 
     // send visbug user preference
     colorschemestate.mode = found_value
-    sendColorScheme()
+    sendColorScheme(tab_id)
 
     return found_value
   })
@@ -75,5 +83,5 @@ platform.contextMenus.onClicked.addListener(({parentMenuItemId, menuItemId}, tab
   platform.storage.sync.set({[schemestoragekey]: menuItemId})
   colorschemestate.mode = menuItemId
 
-  sendColorScheme()
+  sendColorScheme(tab?.id)
 })
diff --git a/extension/visbug.js b/extension/visbug.js
index ac61f8d5..1b0aa535 100644
--- a/extension/visbug.js
+++ b/extension/visbug.js
@@ -11,48 +11,61 @@ var platform = typeof browser === 'undefined'
   ? chrome
   : browser
 
-const toggleIn = ({id:tab_id}) => {
-  // toggle out: it's currently loaded and injected
-  if (state.loaded[tab_id] && state.injected[tab_id]) {
-    platform.scripting.executeScript({
-      target: {tabId: tab_id},
-      files: ['toolbar/eject.js'],
-    })
-    state.injected[tab_id] = false
-  }
+const toggleIn = async ({id:tab_id}) => {
+  try {
+    // toggle out: it's currently loaded and injected
+    if (state.loaded[tab_id] && state.injected[tab_id]) {
+      await platform.scripting.executeScript({
+        target: {tabId: tab_id},
+        files: ['toolbar/eject.js'],
+      })
+      state.injected[tab_id] = false
+    }
 
-  // toggle in: it's loaded and needs injected
-  else if (state.loaded[tab_id] && !state.injected[tab_id]) {
-    platform.scripting.executeScript({
-      target: {tabId: tab_id},
-      files: ['toolbar/restore.js'],
-    })
-    state.injected[tab_id] = true
-    getColorMode()
-    getColorScheme()
-  }
+    // toggle in: it's loaded and needs injected
+    else if (state.loaded[tab_id] && !state.injected[tab_id]) {
+      await platform.scripting.executeScript({
+        target: {tabId: tab_id},
+        files: ['toolbar/restore.js'],
+      })
+      state.injected[tab_id] = true
+      getColorMode(tab_id)
+      getColorScheme(tab_id)
+    }
 
-  // fresh start in tab
-  else {
-    platform.scripting.insertCSS({
-      target: {tabId: tab_id},
-      files: ['toolbar/bundle.css' ],
-    })
-    platform.scripting.executeScript({
-      target: {tabId: tab_id},
-      files: ['toolbar/inject.js'],
-    })
-
-    state.loaded[tab_id]    = true
-    state.injected[tab_id]  = true
-    getColorMode()
-    getColorScheme()
-  }
+    // fresh start in tab
+    else {
+      await platform.scripting.insertCSS({
+        target: {tabId: tab_id},
+        files: ['toolbar/bundle.css' ],
+      })
+      await platform.scripting.executeScript({
+        target: {tabId: tab_id},
+        files: ['toolbar/inject.js'],
+      })
 
-  platform.tabs.onUpdated.addListener(function(tabId) {
-    if (tabId === tab_id)
-      state.loaded[tabId] = false
-  })
+      state.loaded[tab_id]    = true
+      state.injected[tab_id]  = true
+      getColorMode(tab_id)
+      getColorScheme(tab_id)
+    }
+  }
+  catch (error) {
+    state.loaded[tab_id] = false
+    state.injected[tab_id] = false
+    console.error(`Could not toggle VisBug2 in tab ${tab_id}.`, error)
+  }
 }
 
+platform.tabs.onUpdated.addListener((tab_id, change_info) => {
+  if (change_info.status !== 'loading') return
+  delete state.loaded[tab_id]
+  delete state.injected[tab_id]
+})
+
+platform.tabs.onRemoved.addListener(tab_id => {
+  delete state.loaded[tab_id]
+  delete state.injected[tab_id]
+})
+
 gimmeToggle(toggleIn)