diff --git a/cps/helper.py b/cps/helper.py
index a0ab98de..765448bf 100755
--- a/cps/helper.py
+++ b/cps/helper.py
@@ -88,10 +88,10 @@ def make_mobi(book_id, calibrepath):
     if os.path.exists(file_path + u".epub"):
         try:
             p = subprocess.Popen((kindlegen + " \"" + file_path + u".epub\"").encode(sys.getfilesystemencoding()),
-                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
-        except:
+                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        except Exception:
             error_message = _(u"kindlegen failed, no excecution permissions")
-            app.logger.error("make_mobi: "+error_message)
+            app.logger.error("make_mobi: " + error_message)
             return error_message, RET_FAIL
 
         # Poll process for new output until finished
@@ -226,9 +226,11 @@ def send_mail(book_id, kindle_mail, calibrepath):
         msg.attach(get_attachment(formats['mobi']))
     elif 'epub' in formats:
         data, resultCode = make_mobi(book.id, calibrepath)
+        app.logger.error = (data)
         if resultCode == RET_SUCCESS:
             msg.attach(get_attachment(data))
         else:
+
             return data #_("Could not convert epub to mobi")
     elif 'pdf' in formats:
         msg.attach(get_attachment(formats['pdf']))
@@ -305,7 +307,7 @@ def delete_book_gdrive(book):
 def update_dir_stucture(book_id, calibrepath):
     db.session.connection().connection.connection.create_function("title_sort", 1, db.title_sort)
     book = db.session.query(db.Books).filter(db.Books.id == book_id).first()
-    path = os.path.join(calibrepath, book.path)#.replace('/',os.path.sep)).replace('\\',os.path.sep)
+    path = os.path.join(calibrepath, book.path)
 
     authordir = book.path.split('/')[0]
     new_authordir = get_valid_filename(book.authors[0].name)
@@ -333,7 +335,7 @@ def update_dir_structure_gdrive(book_id):
     new_authordir = get_valid_filename(book.authors[0].name)
     titledir = book.path.split('/')[1]
     new_titledir = get_valid_filename(book.title) + " (" + str(book_id) + ")"
-    
+
     if titledir != new_titledir:
         print (titledir)
         gFile=gd.getFileFromEbooksFolder(web.Gdrive.Instance().drive,os.path.dirname(book.path),titledir)
@@ -400,8 +402,8 @@ class Updater(threading.Thread):
         for file in delete_files:
             parts = file.split(os.sep)
             sub = ''
-            for i in range(len(parts)):
-                sub = os.path.join(sub, parts[i])
+            for part in parts:
+                sub = os.path.join(sub, part)
                 if sub == '':
                     sub = os.sep
                 count = 0
@@ -432,7 +434,7 @@ class Updater(threading.Thread):
             logging.getLogger('cps.web').debug('Update on OS-System : ' + sys.platform)
             new_permissions = os.stat(root_dst_dir)
             # print new_permissions
-        for src_dir, dirs, files in os.walk(root_src_dir):
+        for src_dir, __, files in os.walk(root_src_dir):
             dst_dir = src_dir.replace(root_src_dir, root_dst_dir, 1)
             if not os.path.exists(dst_dir):
                 os.makedirs(dst_dir)
diff --git a/cps/ub.py b/cps/ub.py
index dc377cba..7fae5b51 100644
--- a/cps/ub.py
+++ b/cps/ub.py
@@ -349,13 +349,6 @@ class Config:
         else:
             return False
 
-    def role_delete_books(self):
-        if self.config_default_role is not None:
-            return True if self.config_default_role & ROLE_DELETE_BOOKS == ROLE_DELETE_BOOKS else False
-        else:
-            return False
-
-
     def role_passwd(self):
         if self.config_default_role is not None:
             return True if self.config_default_role & ROLE_PASSWD == ROLE_PASSWD else False
@@ -460,13 +453,16 @@ def migrate_Database():
         create=True
     try:
         if create:
-            conn.execute("SELET language_books FROM user")
+            conn = engine.connect()
+            conn.execute("SELECT language_books FROM user")
             session.commit()
     except exc.OperationalError:
         conn = engine.connect()
-        conn.execute("UPDATE user SET 'sidebar_view' = (random_books*"+str(SIDEBAR_RANDOM)+"+ language_books *"+
-                     str(SIDEBAR_LANGUAGE)+"+ series_books *"+str(SIDEBAR_SERIES)+"+ category_books *"+str(SIDEBAR_CATEGORY)+
-                     "+ hot_books *"+str(SIDEBAR_HOT)+"+"+str(SIDEBAR_AUTHOR)+"+"+str(DETAIL_RANDOM)+")")
+        conn.execute("UPDATE user SET 'sidebar_view' = (random_books* :side_random + language_books * :side_lang "
+            "+ series_books * :side_series + category_books * :side_category + hot_books * "
+            ":side_hot + :side_autor + :detail_random)",{'side_random': SIDEBAR_RANDOM,
+            'side_lang': SIDEBAR_LANGUAGE, 'side_series': SIDEBAR_SERIES, 'side_category': SIDEBAR_CATEGORY,
+            'side_hot': SIDEBAR_HOT, 'side_autor': SIDEBAR_AUTHOR, 'detail_random': DETAIL_RANDOM})
         session.commit()
     if session.query(User).filter(User.role.op('&')(ROLE_ANONYMOUS) == ROLE_ANONYMOUS).first() is None:
         create_anonymous_user()
diff --git a/cps/web.py b/cps/web.py
index 5d4d0fef..237dc4ef 100755
--- a/cps/web.py
+++ b/cps/web.py
@@ -77,11 +77,6 @@ import time
 
 current_milli_time = lambda: int(round(time.time() * 1000))
 
-try:
-    from wand.image import Image
-    use_generic_pdf_cover = False
-except ImportError:
-    use_generic_pdf_cover = True
 
 # Global variables
 gdrive_watch_callback_token = 'target=calibreweb-watch_files'
@@ -739,7 +734,7 @@ def feed_author(book_id):
     off = request.args.get("offset")
     if not off:
         off = 0
-    entries, random, pagination = fill_indexpage((int(off) / (int(config.config_books_per_page)) + 1),
+    entries, __, pagination = fill_indexpage((int(off) / (int(config.config_books_per_page)) + 1),
                     db.Books, db.Books.authors.any(db.Authors.id == book_id), db.Books.timestamp.desc())
     xml = render_title_template('feed.xml', entries=entries, pagination=pagination)
     response = make_response(xml)
@@ -1285,8 +1280,8 @@ def stats():
                     lines = lines.decode('utf-8')
                 if re.search('Amazon kindlegen\(', lines):
                     versions['KindlegenVersion'] = lines
-        except:
-            versions['KindlegenVersion'] = _('Excecution permissions missing')
+        except Exception:
+            versions['KindlegenVersion'] = _(u'Excecution permissions missing')
     versions['PythonVersion'] = sys.version
     versions['babel'] = babelVersion
     versions['sqlalchemy'] = sqlalchemyVersion
diff --git a/messages.pot b/messages.pot
index e5f64e14..fc59bccd 100644
--- a/messages.pot
+++ b/messages.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PROJECT VERSION\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2017-07-08 19:46+0200\n"
+"POT-Creation-Date: 2017-07-09 19:16+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -31,33 +31,33 @@ msgstr ""
 msgid "epub format not found for book id: %(book)d"
 msgstr ""
 
-#: cps/helper.py:93
+#: cps/helper.py:90 cps/helper.py:94
 msgid "kindlegen failed, no excecution permissions"
 msgstr ""
 
-#: cps/helper.py:109
+#: cps/helper.py:110
 #, python-format
 msgid "Kindlegen failed with Error %(error)s. Message: %(message)s"
 msgstr ""
 
-#: cps/helper.py:186
+#: cps/helper.py:187
 #, python-format
 msgid "Failed to send mail: %s"
 msgstr ""
 
-#: cps/helper.py:193
+#: cps/helper.py:194
 msgid "Calibre-web test email"
 msgstr ""
 
-#: cps/helper.py:194 cps/helper.py:206
+#: cps/helper.py:195 cps/helper.py:207
 msgid "This email has been sent via calibre web."
 msgstr ""
 
-#: cps/helper.py:203 cps/templates/detail.html:47
+#: cps/helper.py:204 cps/templates/detail.html:43
 msgid "Send to Kindle"
 msgstr ""
 
-#: cps/helper.py:223 cps/helper.py:236
+#: cps/helper.py:224 cps/helper.py:239
 msgid "Could not find any formats suitable for sending by email"
 msgstr ""
 
@@ -445,8 +445,8 @@ msgstr ""
 msgid "Admin"
 msgstr ""
 
-#: cps/templates/admin.html:13 cps/templates/detail.html:22
-#: cps/templates/detail.html:34
+#: cps/templates/admin.html:13 cps/templates/detail.html:21
+#: cps/templates/detail.html:30
 msgid "Download"
 msgstr ""
 
@@ -699,7 +699,7 @@ msgstr ""
 msgid "No Result! Please try anonther keyword."
 msgstr ""
 
-#: cps/templates/book_edit.html:182 cps/templates/detail.html:127
+#: cps/templates/book_edit.html:182 cps/templates/detail.html:126
 #: cps/templates/search_form.html:14
 msgid "Publisher"
 msgstr ""
@@ -809,39 +809,39 @@ msgstr ""
 msgid "Login"
 msgstr ""
 
-#: cps/templates/detail.html:52
+#: cps/templates/detail.html:48
 msgid "Read in browser"
 msgstr ""
 
-#: cps/templates/detail.html:91
+#: cps/templates/detail.html:88
 msgid "Book"
 msgstr ""
 
-#: cps/templates/detail.html:91
+#: cps/templates/detail.html:88
 msgid "of"
 msgstr ""
 
-#: cps/templates/detail.html:97
+#: cps/templates/detail.html:94
 msgid "language"
 msgstr ""
 
-#: cps/templates/detail.html:132
+#: cps/templates/detail.html:131
 msgid "Publishing date"
 msgstr ""
 
-#: cps/templates/detail.html:167
+#: cps/templates/detail.html:168
 msgid "Read"
 msgstr ""
 
-#: cps/templates/detail.html:176
+#: cps/templates/detail.html:177
 msgid "Description:"
 msgstr ""
 
-#: cps/templates/detail.html:187
+#: cps/templates/detail.html:189
 msgid "Add to shelf"
 msgstr ""
 
-#: cps/templates/detail.html:227
+#: cps/templates/detail.html:230
 msgid "Edit metadata"
 msgstr ""
 
@@ -1007,7 +1007,7 @@ msgstr ""
 msgid "Calibre Web ebook catalog"
 msgstr ""
 
-#: cps/templates/read.html:136
+#: cps/templates/read.html:125
 msgid "Reflow text when sidebars are open."
 msgstr ""