Update makethumbnail.py
Line 30 should be indented, otherwise `file_out`  and `file_in`  may result in undefined error
@@ -26,6 +26,7 @@ try:
if file.endswith('.jpg') and not file.endswith('thumb.jpg'):
file_in = os.path.join(root, file)
file_out = (f'{file_in}.thumb.jpg')
+
if not os.path.exists(file_out):
img = Image.open(file_in)
w_percent = (BAS_HEIGHT/float(img.size[1]))
