Update.

src/snek/templates/channel.html

@@ -21,9 +21,9 @@
     
     app.channel._fileManager = null
     app.channel.toggleDrive = function(channelUid){
-        if(app._fileManager){
-            app._fileManager.remove()
-            app._fileManager = null
+        if(app.channel._fileManager){
+            app.channel._fileManager.remove()
+            app.channel._fileManager = null
             document.querySelector('message-list').style.display = 'block'
             return
         }