diff --git a/lector/__main__.py b/lector/__main__.py
index 89fdc87..cfbdf03 100755
--- a/lector/__main__.py
+++ b/lector/__main__.py
@@ -476,7 +476,7 @@ def add_books(self):
         ebooks_string = self._translate('Main_UI', 'eBooks')
         opened_files = QtWidgets.QFileDialog.getOpenFileNames(
             self, dialog_prompt, self.settings['last_open_path'],
-            f'{ebooks_string} ({self.available_parsers})')
+            f'{ebooks_string}({self.available_parsers})')
 
         if not opened_files[0]:
             return
@@ -742,7 +742,7 @@ def show_settings(self, stacked_widget_index):
         else:
             self.settingsDialog.hide()
 
-    #____________________________________________
+    #==================================================================
     # The contentView modification functions are in the guifunctions
     # module. self.profile_functions is the reference here.
 
@@ -763,7 +763,7 @@ def modify_comic_view(self, key_pressed=None):
         self.profile_functions.modify_comic_view(
             signal_sender, key_pressed)
 
-    #____________________________________________
+    #=================================================================
 
     def change_page_view(self, key_pressed=False):
         # Set zoom mode to best fit to
diff --git a/lector/library.py b/lector/library.py
index d8897ed..4cb341b 100644
--- a/lector/library.py
+++ b/lector/library.py
@@ -101,18 +101,7 @@ def generate_model(self, mode, parsed_books=None, is_database_ready=True):
             position = i[5]
             if position:
                 position = pickle.loads(position)
-                if position['is_read']:
-                    position_perc = 1
-                else:
-                    try:
-                        position_perc = (
-                            position['current_block'] / position['total_blocks'])
-                    except (KeyError, ZeroDivisionError):
-                        try:
-                            position_perc = (
-                                position['current_chapter'] / position['total_chapters'])
-                        except KeyError:
-                            position_perc = None
+                position_perc = generate_position_percentage(position)
 
             try:
                 file_exists = os.path.exists(path)
@@ -339,3 +328,23 @@ def prune_models(self, valid_paths):
         # Remove invalid paths from the database as well
         database.DatabaseFunctions(
             self.main_window.database_path).delete_from_database('Path', invalid_paths)
+
+
+def generate_position_percentage(position):
+    if not position:
+        return None
+
+    if position['is_read']:
+        position_perc = 1
+    else:
+        try:
+            position_perc = (
+                position['current_block'] / position['total_blocks'])
+        except (KeyError, ZeroDivisionError):
+            try:
+                position_perc = (
+                    position['current_chapter'] / position['total_chapters'])
+            except KeyError:
+                position_perc = None
+
+    return position_perc
diff --git a/lector/logger.py b/lector/logger.py
index 3e8770e..45f7128 100644
--- a/lector/logger.py
+++ b/lector/logger.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-VERSION = '0.5.0'
+VERSION = '0.5.1'
 
 import os
 import logging
diff --git a/lector/sorter.py b/lector/sorter.py
index 73838e3..9789dd8 100644
--- a/lector/sorter.py
+++ b/lector/sorter.py
@@ -201,7 +201,9 @@ def read_book(self, filename):
                 break
 
         if not valid_extension:
-            logger.error('Unsupported extension: ' + filename)
+            this_error = 'Unsupported extension: ' + filename
+            self.errors.append(this_error)
+            logger.error(this_error)
             return
 
         book_ref = sorter[file_extension](filename, self.temp_dir, file_md5)