diff --git a/supysonic/api/errors.py b/supysonic/api/errors.py
index 6d03629..55da786 100644
--- a/supysonic/api/errors.py
+++ b/supysonic/api/errors.py
@@ -3,7 +3,7 @@
 # This file is part of Supysonic.
 # Supysonic is a Python implementation of the Subsonic server API.
 #
-# Copyright (C) 2018 Alban 'spl0k' Féron
+# Copyright (C) 2018-2019 Alban 'spl0k' Féron
 #
 # Distributed under terms of the GNU AGPLv3 license.
 
@@ -23,7 +23,7 @@ def value_error(e):
 @api.errorhandler(BadRequestKeyError)
 def key_error(e):
     rollback()
-    return MissingParameter(e.args[0])
+    return MissingParameter()
 
 @api.errorhandler(ObjectNotFound)
 def not_found(e):
diff --git a/supysonic/api/exceptions.py b/supysonic/api/exceptions.py
index 62cf477..6bfec0e 100644
--- a/supysonic/api/exceptions.py
+++ b/supysonic/api/exceptions.py
@@ -3,7 +3,7 @@
 # This file is part of Supysonic.
 # Supysonic is a Python implementation of the Subsonic server API.
 #
-# Copyright (C) 2018 Alban 'spl0k' Féron
+# Copyright (C) 2018-2019 Alban 'spl0k' Féron
 #
 # Distributed under terms of the GNU AGPLv3 license.
 
@@ -42,9 +42,9 @@ class UnsupportedParameter(GenericError):
 class MissingParameter(SubsonicAPIException):
     api_code = 10
 
-    def __init__(self, param, *args, **kwargs):
+    def __init__(self, *args, **kwargs):
         super(MissingParameter, self).__init__(*args, **kwargs)
-        self.message = "Required parameter '{}' is missing.".format(param)
+        self.message = "A required parameter is missing."
 
 class ClientMustUpgrade(SubsonicAPIException):
     api_code = 20
diff --git a/supysonic/api/media.py b/supysonic/api/media.py
index 98cd7cd..49ae9a7 100644
--- a/supysonic/api/media.py
+++ b/supysonic/api/media.py
@@ -3,7 +3,7 @@
 # This file is part of Supysonic.
 # Supysonic is a Python implementation of the Subsonic server API.
 #
-# Copyright (C) 2013-2018 Alban 'spl0k' Féron
+# Copyright (C) 2013-2019 Alban 'spl0k' Féron
 #               2018-2019 Carey 'pR0Ps' Metcalfe
 #
 # Distributed under terms of the GNU AGPLv3 license.
@@ -65,7 +65,7 @@ def stream_media():
     src_suffix = res.suffix()
     dst_suffix = res.suffix()
     dst_bitrate = res.bitrate
-    dst_mimetype = res.content_type
+    dst_mimetype = res.mimetype
 
     prefs = request.client
     if prefs.format:
@@ -153,7 +153,7 @@ def download_media():
 
     try: # Track -> direct download
         rv = Track[uid]
-        return send_file(rv.path, mimetype = rv.content_type, conditional=True)
+        return send_file(rv.path, mimetype = rv.mimetype, conditional=True)
     except ObjectNotFound:
         pass
 
diff --git a/supysonic/db.py b/supysonic/db.py
index f283e8e..cb85005 100644
--- a/supysonic/db.py
+++ b/supysonic/db.py
@@ -3,7 +3,7 @@
 # This file is part of Supysonic.
 # Supysonic is a Python implementation of the Subsonic server API.
 #
-# Copyright (C) 2013-2018 Alban 'spl0k' Féron
+# Copyright (C) 2013-2019 Alban 'spl0k' Féron
 #
 # Distributed under terms of the GNU AGPLv3 license.
 
@@ -31,7 +31,7 @@ try:
 except ImportError:
     from urlparse import urlparse, parse_qsl
 
-SCHEMA_VERSION = '20190324'
+SCHEMA_VERSION = '20190518'
 
 def now():
     return datetime.now().replace(microsecond = 0)
@@ -74,11 +74,11 @@ class Folder(PathMixin, db.Entity):
 
     id = PrimaryKey(UUID, default = uuid4)
     root = Required(bool, default = False)
-    name = Required(str)
-    path = Required(str, 4096) # unique
+    name = Required(str, autostrip = False)
+    path = Required(str, 4096, autostrip = False) # unique
     _path_hash = Required(buffer, column = 'path_hash')
     created = Required(datetime, precision = 0, default = now)
-    cover_art = Optional(str, nullable = True)
+    cover_art = Optional(str, nullable = True, autostrip = False)
     last_scan = Required(int, default = 0)
 
     parent = Optional(lambda: Folder, reverse = 'children', column = 'parent_id')
@@ -227,9 +227,8 @@ class Track(PathMixin, db.Entity):
 
     bitrate = Required(int)
 
-    path = Required(str, 4096) # unique
+    path = Required(str, 4096, autostrip = False) # unique
     _path_hash = Required(buffer, column = 'path_hash')
-    content_type = Required(str)
     created = Required(datetime, precision = 0, default = now)
     last_modification = Required(int)
 
@@ -254,7 +253,7 @@ class Track(PathMixin, db.Entity):
             artist = self.artist.name,
             track = self.number,
             size = os.path.getsize(self.path) if os.path.isfile(self.path) else -1,
-            contentType = self.content_type,
+            contentType = self.mimetype,
             suffix = self.suffix(),
             duration = self.duration,
             bitRate = self.bitrate,
@@ -296,6 +295,10 @@ class Track(PathMixin, db.Entity):
 
         return info
 
+    @property
+    def mimetype(self):
+        return mimetypes.guess_type(self.path, False)[0] or 'application/octet-stream'
+
     def duration_str(self):
         ret = '%02i:%02i' % ((self.duration % 3600) / 60, self.duration % 60)
         if self.duration >= 3600:
diff --git a/supysonic/scanner.py b/supysonic/scanner.py
index 5aeb36b..c6d0eb8 100644
--- a/supysonic/scanner.py
+++ b/supysonic/scanner.py
@@ -9,7 +9,6 @@
 
 import logging
 import os, os.path
-import mimetypes
 import mutagen
 import time
 
@@ -224,7 +223,6 @@ class Scanner(Thread):
         trdict['has_art']  = bool(Track._extract_cover_art(path))
 
         trdict['bitrate']  = int(tag.info.bitrate if hasattr(tag.info, 'bitrate') else os.path.getsize(path) * 8 / tag.info.length) // 1000
-        trdict['content_type'] = mimetypes.guess_type(path, False)[0] or 'application/octet-stream'
         trdict['last_modification'] = mtime
 
         tralbum = self.__find_album(albumartist, album)
@@ -293,6 +291,9 @@ class Scanner(Thread):
         if not isinstance(dirpath, strtype): # pragma: nocover
             raise TypeError('Expecting string, got ' + str(type(dirpath)))
 
+        if not os.path.exists(dirpath):
+            return
+
         folder = Folder.get(path = dirpath)
         if folder is None:
             return
diff --git a/supysonic/schema/migration/mysql/20190518.sql b/supysonic/schema/migration/mysql/20190518.sql
new file mode 100644
index 0000000..9e4ce8e
--- /dev/null
+++ b/supysonic/schema/migration/mysql/20190518.sql
@@ -0,0 +1 @@
+ALTER TABLE track DROP COLUMN content_type;
diff --git a/supysonic/schema/migration/postgres/20190518.sql b/supysonic/schema/migration/postgres/20190518.sql
new file mode 100644
index 0000000..9e4ce8e
--- /dev/null
+++ b/supysonic/schema/migration/postgres/20190518.sql
@@ -0,0 +1 @@
+ALTER TABLE track DROP COLUMN content_type;
diff --git a/supysonic/schema/migration/sqlite/20190518.sql b/supysonic/schema/migration/sqlite/20190518.sql
new file mode 100644
index 0000000..5c4be5e
--- /dev/null
+++ b/supysonic/schema/migration/sqlite/20190518.sql
@@ -0,0 +1,43 @@
+DROP INDEX index_track_album_id_fk;
+DROP INDEX index_track_artist_id_fk;
+DROP INDEX index_track_folder_id_fk;
+DROP INDEX index_track_root_folder_id_fk;
+DROP INDEX index_track_path;
+
+ALTER TABLE track RENAME TO track_old;
+
+CREATE TABLE IF NOT EXISTS track (
+    id CHAR(36) PRIMARY KEY,
+    disc INTEGER NOT NULL,
+    number INTEGER NOT NULL,
+    title VARCHAR(256) NOT NULL COLLATE NOCASE,
+    year INTEGER,
+    genre VARCHAR(256),
+    duration INTEGER NOT NULL,
+    has_art BOOLEAN NOT NULL DEFAULT false,
+    album_id CHAR(36) NOT NULL REFERENCES album,
+    artist_id CHAR(36) NOT NULL REFERENCES artist,
+    bitrate INTEGER NOT NULL,
+    path VARCHAR(4096) NOT NULL,
+    path_hash BLOB NOT NULL,
+    created DATETIME NOT NULL,
+    last_modification INTEGER NOT NULL,
+    play_count INTEGER NOT NULL,
+    last_play DATETIME,
+    root_folder_id CHAR(36) NOT NULL REFERENCES folder,
+    folder_id CHAR(36) NOT NULL REFERENCES folder
+);
+CREATE INDEX IF NOT EXISTS index_track_album_id_fk ON track(album_id);
+CREATE INDEX IF NOT EXISTS index_track_artist_id_fk ON track(artist_id);
+CREATE INDEX IF NOT EXISTS index_track_folder_id_fk ON track(folder_id);
+CREATE INDEX IF NOT EXISTS index_track_root_folder_id_fk ON track(root_folder_id);
+CREATE UNIQUE INDEX IF NOT EXISTS index_track_path ON track(path_hash);
+
+INSERT INTO track(id, disc, number, title, year, genre, duration, has_art, album_id, artist_id, bitrate, path, path_hash, created, last_modification, play_count, last_play, root_folder_id, folder_id)
+SELECT id, disc, number, title, year, genre, duration, has_art, album_id, artist_id, bitrate, path, path_hash, created, last_modification, play_count, last_play, root_folder_id, folder_id
+FROM track_old;
+
+DROP TABLE track_old;
+
+COMMIT;
+VACUUM;
diff --git a/supysonic/schema/mysql.sql b/supysonic/schema/mysql.sql
index aad2101..864b2a8 100644
--- a/supysonic/schema/mysql.sql
+++ b/supysonic/schema/mysql.sql
@@ -37,7 +37,6 @@ CREATE TABLE IF NOT EXISTS track (
     bitrate INTEGER NOT NULL,
     path VARCHAR(4096) NOT NULL,
     path_hash BINARY(20) UNIQUE NOT NULL,
-    content_type VARCHAR(32) NOT NULL,
     created DATETIME NOT NULL,
     last_modification INTEGER NOT NULL,
     play_count INTEGER NOT NULL,
diff --git a/supysonic/schema/postgres.sql b/supysonic/schema/postgres.sql
index 32ee459..95c9e94 100644
--- a/supysonic/schema/postgres.sql
+++ b/supysonic/schema/postgres.sql
@@ -37,7 +37,6 @@ CREATE TABLE IF NOT EXISTS track (
     bitrate INTEGER NOT NULL,
     path VARCHAR(4096) NOT NULL,
     path_hash BYTEA UNIQUE NOT NULL,
-    content_type VARCHAR(32) NOT NULL,
     created TIMESTAMP NOT NULL,
     last_modification INTEGER NOT NULL,
     play_count INTEGER NOT NULL,
diff --git a/supysonic/schema/sqlite.sql b/supysonic/schema/sqlite.sql
index fae2591..23a7ff8 100644
--- a/supysonic/schema/sqlite.sql
+++ b/supysonic/schema/sqlite.sql
@@ -38,7 +38,6 @@ CREATE TABLE IF NOT EXISTS track (
     bitrate INTEGER NOT NULL,
     path VARCHAR(4096) NOT NULL,
     path_hash BLOB NOT NULL,
-    content_type VARCHAR(32) NOT NULL,
     created DATETIME NOT NULL,
     last_modification INTEGER NOT NULL,
     play_count INTEGER NOT NULL,
diff --git a/tests/__init__.py b/tests/__init__.py
index 6df5548..cdc0b64 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -19,6 +19,7 @@ from .issue101 import Issue101TestCase
 from .issue129 import Issue129TestCase
 from .issue133 import Issue133TestCase
 from .issue139 import Issue139TestCase
+from .issue148 import Issue148TestCase
 
 def suite():
     suite = unittest.TestSuite()
@@ -31,6 +32,7 @@ def suite():
     suite.addTest(unittest.makeSuite(Issue129TestCase))
     suite.addTest(unittest.makeSuite(Issue133TestCase))
     suite.addTest(unittest.makeSuite(Issue139TestCase))
+    suite.addTest(unittest.makeSuite(Issue148TestCase))
 
     return suite
 
diff --git a/tests/api/test_album_songs.py b/tests/api/test_album_songs.py
index e77d5e7..7ff080e 100644
--- a/tests/api/test_album_songs.py
+++ b/tests/api/test_album_songs.py
@@ -39,7 +39,6 @@ class AlbumSongsTestCase(ApiTestBase):
                 root_folder = folder,
                 duration = 2,
                 bitrate = 320,
-                content_type = 'audio/mpeg',
                 last_modification = 0
             )
 
diff --git a/tests/api/test_annotation.py b/tests/api/test_annotation.py
index 52f81f7..b9aae03 100644
--- a/tests/api/test_annotation.py
+++ b/tests/api/test_annotation.py
@@ -37,7 +37,6 @@ class AnnotationTestCase(ApiTestBase):
                 root_folder = root,
                 duration = 2,
                 bitrate = 320,
-                content_type = 'audio/mpeg',
                 last_modification = 0
             )
 
diff --git a/tests/api/test_browse.py b/tests/api/test_browse.py
index 05ca9cb..990590f 100644
--- a/tests/api/test_browse.py
+++ b/tests/api/test_browse.py
@@ -54,7 +54,6 @@ class BrowseTestCase(ApiTestBase):
                             artist = artist,
                             bitrate = 320,
                             path = 'tests/assets/{0}rtist/{0}{1}lbum/{2}'.format(letter, lether, song),
-                            content_type = 'audio/mpeg',
                             last_modification = 0,
                             root_folder = root,
                             folder = afolder
diff --git a/tests/api/test_media.py b/tests/api/test_media.py
index 6348e70..fec96d7 100644
--- a/tests/api/test_media.py
+++ b/tests/api/test_media.py
@@ -48,7 +48,6 @@ class MediaTestCase(ApiTestBase):
                 folder = folder,
                 duration = 2,
                 bitrate = 320,
-                content_type = 'audio/mpeg',
                 last_modification = 0
             )
             self.trackid = track.id
@@ -66,7 +65,6 @@ class MediaTestCase(ApiTestBase):
                     folder = folder,
                     duration = 2,
                     bitrate = 320,
-                    content_type = 'audio/{0}'.format(self.formats[i][1]),
                     last_modification = 0
                 )
                 self.formats[i] = track_embeded_art.id
@@ -82,7 +80,6 @@ class MediaTestCase(ApiTestBase):
 
         rv = self.client.get('/rest/stream.view', query_string = { 'u': 'alice', 'p': 'Alic3', 'c': 'tests', 'id': str(self.trackid) })
         self.assertEqual(rv.status_code, 200)
-        self.assertEqual(rv.mimetype, 'audio/mpeg')
         self.assertEqual(len(rv.data), 23)
         with db_session:
             self.assertEqual(Track[self.trackid].play_count, 1)
@@ -95,7 +92,6 @@ class MediaTestCase(ApiTestBase):
         # download single file
         rv = self.client.get('/rest/download.view', query_string = { 'u': 'alice', 'p': 'Alic3', 'c': 'tests', 'id': str(self.trackid) })
         self.assertEqual(rv.status_code, 200)
-        self.assertEqual(rv.mimetype, 'audio/mpeg')
         self.assertEqual(len(rv.data), 23)
         with db_session:
             self.assertEqual(Track[self.trackid].play_count, 0)
diff --git a/tests/api/test_playlist.py b/tests/api/test_playlist.py
index 0e9b063..5e3e682 100644
--- a/tests/api/test_playlist.py
+++ b/tests/api/test_playlist.py
@@ -36,7 +36,6 @@ class PlaylistTestCase(ApiTestBase):
                     artist = artist,
                     bitrate = 320,
                     path = 'tests/assets/' + song,
-                    content_type = 'audio/mpeg',
                     last_modification = 0,
                     root_folder = root,
                     folder = root
diff --git a/tests/api/test_search.py b/tests/api/test_search.py
index 8216257..1f6b55d 100644
--- a/tests/api/test_search.py
+++ b/tests/api/test_search.py
@@ -47,7 +47,6 @@ class SearchTestCase(ApiTestBase):
                             artist = artist,
                             bitrate = 320,
                             path = 'tests/assets/{0}rtist/{0}{1}lbum/{2}'.format(letter, lether, song),
-                            content_type = 'audio/mpeg',
                             last_modification = 0,
                             root_folder = root,
                             folder = afolder
diff --git a/tests/base/test_db.py b/tests/base/test_db.py
index e99c7a5..1095599 100644
--- a/tests/base/test_db.py
+++ b/tests/base/test_db.py
@@ -74,7 +74,6 @@ class DbTestCase(unittest.TestCase):
             has_art = True,
             bitrate = 320,
             path = 'tests/assets/formats/silence.ogg',
-            content_type = 'audio/ogg',
             last_modification = 1234,
             root_folder = root,
             folder = child
@@ -89,7 +88,6 @@ class DbTestCase(unittest.TestCase):
             duration = 5,
             bitrate = 96,
             path = 'tests/assets/23bytes',
-            content_type = 'audio/mpeg',
             last_modification = 1234,
             root_folder = root,
             folder = child
@@ -110,7 +108,6 @@ class DbTestCase(unittest.TestCase):
             has_art = has_art,
             bitrate = 96,
             path = 'tests/assets/formats/silence.flac',
-            content_type = 'audio/flac',
             last_modification = 1234,
             root_folder = root,
             folder = folder
diff --git a/tests/frontend/test_playlist.py b/tests/frontend/test_playlist.py
index 67bdb22..453c460 100644
--- a/tests/frontend/test_playlist.py
+++ b/tests/frontend/test_playlist.py
@@ -35,7 +35,6 @@ class PlaylistTestCase(FrontendTestBase):
                 duration = 2,
                 disc = 1,
                 number = 1,
-                content_type = 'audio/mpeg',
                 bitrate = 320,
                 last_modification = 0
             )
diff --git a/tests/issue148.py b/tests/issue148.py
new file mode 100644
index 0000000..15bfb46
--- /dev/null
+++ b/tests/issue148.py
@@ -0,0 +1,46 @@
+# coding: utf-8
+#
+# This file is part of Supysonic.
+# Supysonic is a Python implementation of the Subsonic server API.
+#
+# Copyright (C) 2019 Alban 'spl0k' Féron
+#
+# Distributed under terms of the GNU AGPLv3 license.
+
+import os.path
+import shutil
+import tempfile
+import unittest
+
+from pony.orm import db_session
+
+from supysonic.db import init_database, release_database
+from supysonic.db import Folder
+from supysonic.managers.folder import FolderManager
+from supysonic.scanner import Scanner
+
+class Issue148TestCase(unittest.TestCase):
+    def setUp(self):
+        self.__dir = tempfile.mkdtemp()
+        init_database('sqlite:')
+        with db_session:
+            FolderManager.add('folder', self.__dir)
+
+    def tearDown(self):
+        release_database()
+        shutil.rmtree(self.__dir)
+
+    def test_issue(self):
+        subdir = os.path.join(self.__dir, '  ')
+        os.makedirs(subdir)
+        shutil.copyfile('tests/assets/folder/silence.mp3', os.path.join(subdir, 'silence.mp3'))
+
+        scanner = Scanner()
+        scanner.queue_folder('folder')
+        scanner.run()
+        del scanner
+
+
+if __name__ == '__main__':
+    unittest.main()
+
diff --git a/tests/managers/test_manager_folder.py b/tests/managers/test_manager_folder.py
index 7070734..9198057 100644
--- a/tests/managers/test_manager_folder.py
+++ b/tests/managers/test_manager_folder.py
@@ -59,7 +59,6 @@ class FolderManagerTestCase(unittest.TestCase):
             folder = root,
             root_folder = root,
             duration = 2,
-            content_type = 'audio/mpeg',
             bitrate = 320,
             last_modification = 0
         )
diff --git a/tests/managers/test_manager_user.py b/tests/managers/test_manager_user.py
index dcb52ee..07a5b89 100644
--- a/tests/managers/test_manager_user.py
+++ b/tests/managers/test_manager_user.py
@@ -48,7 +48,6 @@ class UserManagerTestCase(unittest.TestCase):
             path = 'tests/assets/empty',
             folder = folder,
             root_folder = folder,
-            content_type = 'audio/mpeg',
             bitrate = 320,
             last_modification = 0
         )