sometimes if you select a file, then click another button
besides "make hash file" then you have to restart the
program before it can make a hash file because when
you click "make hash-file" it says "can't open hash-file"
for example,
open the program
select a file
click "select has file" but then cancel
then try to "make hash-file"
not a very big problem, but i just wanted to tell you