diff --git a/frontend/apps/reader/modules/readermenu.lua b/frontend/apps/reader/modules/readermenu.lua
index e9d3e75be..86633925e 100644
--- a/frontend/apps/reader/modules/readermenu.lua
+++ b/frontend/apps/reader/modules/readermenu.lua
@@ -3,7 +3,6 @@ local Device = require("device")
 local Event = require("ui/event")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local Screensaver = require("ui/screensaver")
-local QuickStart = require("ui/quickstart")
 local UIManager = require("ui/uimanager")
 local logger = require("logger")
 local dbg = require("dbg")
@@ -43,18 +42,7 @@ function ReaderMenu:init()
             callback = function()
                 self:onTapCloseMenu()
                 self.ui:onClose()
-                local lastdir
-                local last_file = G_reader_settings:readSetting("lastfile")
-                -- ignore quickstart guide as last_file so we can go back to home dir
-                if last_file and last_file ~= QuickStart.quickstart_filename then
-                    lastdir = last_file:match("(.*)/")
-                end
-                local FileManager = require("apps/filemanager/filemanager")
-                if FileManager.instance then
-                    FileManager.instance:reinit(lastdir)
-                else
-                    FileManager:showFiles(lastdir)
-                end
+                self.ui:showFileManager()
             end,
         },
         main = {
diff --git a/frontend/apps/reader/readerui.lua b/frontend/apps/reader/readerui.lua
index 5c8916dfd..9eb5b532d 100644
--- a/frontend/apps/reader/readerui.lua
+++ b/frontend/apps/reader/readerui.lua
@@ -1,55 +1,54 @@
-local InputContainer = require("ui/widget/container/inputcontainer")
-local DocumentRegistry = require("document/documentregistry")
-local Screenshoter = require("ui/widget/screenshoter")
-local InfoMessage = require("ui/widget/infomessage")
-local InputDialog = require("ui/widget/inputdialog")
-local ConfirmBox = require("ui/widget/confirmbox")
-local lfs = require("libs/libkoreader-lfs")
-local DocSettings = require("docsettings")
-local UIManager = require("ui/uimanager")
-local Geom = require("ui/geometry")
-local Device = require("device")
-local Screen = require("device").screen
-local Event = require("ui/event")
-local Cache = require("cache")
-local logger = require("logger")
-local T = require("ffi/util").template
-local _ = require("gettext")
+--[[
+ReaderUI is an abstraction for a reader interface.
 
-local ReaderView = require("apps/reader/modules/readerview")
-local ReaderZooming = require("apps/reader/modules/readerzooming")
+It works using data gathered from a document interface.
+]]--
+
+local Cache = require("cache")
+local ConfirmBox = require("ui/widget/confirmbox")
+local Device = require("device")
+local DocSettings = require("docsettings")
+local DocumentRegistry = require("document/documentregistry")
+local Event = require("ui/event")
+local FileManagerHistory = require("apps/filemanager/filemanagerhistory")
+local Geom = require("ui/geometry")
+local InfoMessage = require("ui/widget/infomessage")
+local InputContainer = require("ui/widget/container/inputcontainer")
+local InputDialog = require("ui/widget/inputdialog")
+local PluginLoader = require("pluginloader")
+local ReaderActivityIndicator = require("apps/reader/modules/readeractivityindicator")
+local ReaderBookmark = require("apps/reader/modules/readerbookmark")
+local ReaderConfig = require("apps/reader/modules/readerconfig")
+local ReaderCoptListener = require("apps/reader/modules/readercoptlistener")
+local ReaderCropping = require("apps/reader/modules/readercropping")
+local ReaderDictionary = require("apps/reader/modules/readerdictionary")
+local ReaderFont = require("apps/reader/modules/readerfont")
+local ReaderFrontLight = require("apps/reader/modules/readerfrontlight")
+local ReaderGoto = require("apps/reader/modules/readergoto")
+local ReaderHinting = require("apps/reader/modules/readerhinting")
+local ReaderHighlight = require("apps/reader/modules/readerhighlight")
+local ReaderHyphenation = require("apps/reader/modules/readerhyphenation")
+local ReaderKoptListener = require("apps/reader/modules/readerkoptlistener")
+local ReaderLink = require("apps/reader/modules/readerlink")
+local ReaderMenu = require("apps/reader/modules/readermenu")
 local ReaderPanning = require("apps/reader/modules/readerpanning")
 local ReaderRotation = require("apps/reader/modules/readerrotation")
 local ReaderPaging = require("apps/reader/modules/readerpaging")
 local ReaderRolling = require("apps/reader/modules/readerrolling")
-local ReaderToc = require("apps/reader/modules/readertoc")
-local ReaderBookmark = require("apps/reader/modules/readerbookmark")
-local ReaderFont = require("apps/reader/modules/readerfont")
-local ReaderTypeset = require("apps/reader/modules/readertypeset")
-local ReaderMenu = require("apps/reader/modules/readermenu")
-local ReaderGoto = require("apps/reader/modules/readergoto")
-local ReaderConfig = require("apps/reader/modules/readerconfig")
-local ReaderCropping = require("apps/reader/modules/readercropping")
-local ReaderKoptListener = require("apps/reader/modules/readerkoptlistener")
-local ReaderCoptListener = require("apps/reader/modules/readercoptlistener")
-local ReaderHinting = require("apps/reader/modules/readerhinting")
-local ReaderHighlight = require("apps/reader/modules/readerhighlight")
-local ReaderFrontLight = require("apps/reader/modules/readerfrontlight")
-local ReaderDictionary = require("apps/reader/modules/readerdictionary")
-local ReaderWikipedia = require("apps/reader/modules/readerwikipedia")
-local ReaderHyphenation = require("apps/reader/modules/readerhyphenation")
-local ReaderActivityIndicator = require("apps/reader/modules/readeractivityindicator")
-local FileManagerHistory = require("apps/filemanager/filemanagerhistory")
 local ReaderSearch = require("apps/reader/modules/readersearch")
-local ReaderLink = require("apps/reader/modules/readerlink")
 local ReaderStatus = require("apps/reader/modules/readerstatus")
-local PluginLoader = require("pluginloader")
-
---[[
-This is an abstraction for a reader interface
-
-it works using data gathered from a document interface
-]]--
+local ReaderToc = require("apps/reader/modules/readertoc")
+local ReaderTypeset = require("apps/reader/modules/readertypeset")
+local ReaderView = require("apps/reader/modules/readerview")
+local ReaderWikipedia = require("apps/reader/modules/readerwikipedia")
+local ReaderZooming = require("apps/reader/modules/readerzooming")
+local Screenshoter = require("ui/widget/screenshoter")
+local UIManager = require("ui/uimanager")
+local lfs = require("libs/libkoreader-lfs")
+local logger = require("logger")
+local _ = require("gettext")
+local Screen = require("device").screen
+local T = require("ffi/util").template
 
 local ReaderUI = InputContainer:new{
     name = "ReaderUI",
@@ -354,6 +353,22 @@ function ReaderUI:init()
     self.postReaderCallback = nil
 end
 
+function ReaderUI:showFileManager()
+    local FileManager = require("apps/filemanager/filemanager")
+    local QuickStart = require("ui/quickstart")
+    local lastdir
+    local last_file = G_reader_settings:readSetting("lastfile")
+    -- ignore quickstart guide as last_file so we can go back to home dir
+    if last_file and last_file ~= QuickStart.quickstart_filename then
+        lastdir = last_file:match("(.*)/")
+    end
+    if FileManager.instance then
+        FileManager.instance:reinit(lastdir)
+    else
+        FileManager:showFiles(lastdir)
+    end
+end
+
 function ReaderUI:showReader(file)
     logger.dbg("show reader ui")
     require("readhistory"):addItem(file)
@@ -393,8 +408,9 @@ function ReaderUI:doShowReader(file)
     local document = DocumentRegistry:openDocument(file)
     if not document then
         UIManager:show(InfoMessage:new{
-            text = _("No reader engine for this file.")
+            text = _("No reader engine for this file or invalid file.")
         })
+        self:showFileManager()
         return
     end
     if document.is_locked then
@@ -404,6 +420,7 @@ function ReaderUI:doShowReader(file)
         if coroutine.running() then
             local unlock_success = coroutine.yield()
             if not unlock_success then
+                self:showFileManager()
                 return
             end
         end