Can't copy text on "about:" pages. This is a webextension or Firefox limitation.

background.js

@@ -55,16 +55,28 @@ browser.contextMenus.create({
 	onclick: function(){
     browser.tabs.query({ currentWindow: true, active: true }, function(tabs) {
       tab = tabs[0];
+      if(tab.url.includes("about:") == true){
+        shareURL("",tab);
+      }
+      else
+      {
     browser.tabs.sendMessage(tab.id, {method: "getSelection"}).then(response => {
   	shareURL(response.response,tab);
     }).catch(onError);
+    }
   });
 	},
 	contexts: ["all"]
 });
 
 browser.browserAction.onClicked.addListener((tab) => {
+  if(tab.url.includes("about:") == true){
+    shareURL("",tab);
+  }
+  else
+  {
 	browser.tabs.sendMessage(tab.id, {method: "getSelection"}).then(response => {
 	shareURL(response.response,tab);
   }).catch(onError);
+  }
 });

manifest.json

@@ -1,7 +1,7 @@
 {
 	"manifest_version" : 2,
 	"name": "Add to (Semantic)Scuttle",
-	"version" : "0.7.1",
+	"version" : "0.7.2",
 	"description" : "Add bookmarks to a (Semantic)Scuttle instance, a social bookmarking tool experimenting with tags and collaborative tag descriptions.",
 	"homepage_url" : "https://addons.mozilla.org/fr/firefox/addon/add-to-semantic-scuttle/",
 	"icons" : {