diff --git a/client/ext/filesystem/filesystem.js b/client/ext/filesystem/filesystem.js
index 808e2f92ca9..7919a0e63b5 100644
--- a/client/ext/filesystem/filesystem.js
+++ b/client/ext/filesystem/filesystem.js
@@ -60,8 +60,10 @@ module.exports = ext.register("ext/filesystem/filesystem", {
         }
 
         var node = tree.selected;
-        if (!node)
+        if (!node && tree.xmlRoot)
             node = tree.xmlRoot.selectSingleNode("folder");
+        if (!node)
+            return;
         if (node.getAttribute("type") != "folder" && node.tagName != "folder")
             node = node.parentNode;
 
diff --git a/client/ext/themes/themes.js b/client/ext/themes/themes.js
index 137984dfea2..0392dcb3a66 100644
--- a/client/ext/themes/themes.js
+++ b/client/ext/themes/themes.js
@@ -7,6 +7,7 @@
 
 define(function(require, exports, module) {
 
+var ide = require("core/ide");
 var ext = require("core/ext");
 var settings = require("ext/settings/settings");
 
diff --git a/client/ext/tree/tree.xml b/client/ext/tree/tree.xml
index c1b89589594..8eca8c9067d 100644
--- a/client/ext/tree/tree.xml
+++ b/client/ext/tree/tree.xml
@@ -79,8 +79,8 @@
           contextmenu="mnuCtxTree" multiselect="false" reselectable="true" 
           onbeforemove="this.disable();" autoselect="false"
           onbeforeremove="return remove()" disabled="{{!stServerConnected.active}}"
-          flex="1" anchors="0 0 0 0" onmouseover="require('ext/tree/tree').onTreeOver()"
-          onmouseout="require('ext/tree/tree').onTreeOut()"
+          flex="1" anchors="0 0 0 0" onmouseover="var tree = require('ext/tree/tree');if (tree) tree.onTreeOver()"
+          onmouseout="var tree = require('ext/tree/tree');if (tree) tree.onTreeOut()"
         >
             <a:each match="[project|file|folder]" sort="[@name]" sort-method="filesort">
                 <a:insert match="[folder]" get="{location.host and davProject.readdir([@path])}" />